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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Ho(SiNi5)2 by Materials Project

Ho(Ni5Si)2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. Ho is bonded in a 12-coordinate geometry to sixteen Ni and four equivalent Si atoms. There are a spread of Ho–Ni bond distances ranging from 2.88–3.06 Å. All Ho–Si bond lengths are 3.16 Å. There are three inequivalent Ni sites. In the first Ni site, Ni is bonded to two equivalent Ho, eight Ni, and two equivalent Si atoms to form NiHo2Si2Ni8 cuboctahedra that share corners with six equivalent SiHo2Ni10 cuboctahedra, corners with twelve NiHo2Si2Ni8 cuboctahedra, edges with four equivalent NiHo2Si2Ni8 cuboctahedra, edges with four equivalent SiHo2Ni10 cuboctahedra, faces with two equivalent SiHo2Ni10 cuboctahedra, and faces with twelve NiHo2Si2Ni8 cuboctahedra. There are four shorter (2.41 Å) and four longer (2.47 Å) Ni–Ni bond lengths. Both Ni–Si bond lengths are 2.33 Å. In the second Ni site, Ni is bonded in a 12-coordinate geometry to one Ho, eleven Ni, and two equivalent Si atoms. There are a spread of Ni–Ni bond distances ranging from 2.40–2.97 Å. Both Ni–Si bond lengths are 2.52 Å. In the third Ni site, Ni is bonded to two equivalent Ho, eight Ni, and two equivalent Si atoms to form distorted NiHo2Si2Ni8 cuboctahedra that share corners with four equivalent SiHo2Ni10 cuboctahedra, corners with fourteen NiHo2Si2Ni8 cuboctahedra, edges with two equivalent SiHo2Ni10 cuboctahedra, edges with five NiHo2Si2Ni8 cuboctahedra, faces with four equivalent SiHo2Ni10 cuboctahedra, and faces with eleven NiHo2Si2Ni8 cuboctahedra. Both Ni–Ni bond lengths are 2.57 Å. Both Ni–Si bond lengths are 2.31 Å. Si is bonded to two equivalent Ho and ten Ni atoms to form distorted SiHo2Ni10 cuboctahedra that share corners with four equivalent SiHo2Ni10 cuboctahedra, corners with fourteen NiHo2Si2Ni8 cuboctahedra, edges with eight NiHo2Si2Ni8 cuboctahedra, faces with four equivalent SiHo2Ni10 cuboctahedra, and faces with ten NiHo2Si2Ni8 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho(MnGa)6 by Materials Project

Ho(MnGa)6 crystallizes in the orthorhombic Fmmm space group. The structure is three-dimensional. Ho is bonded in a 12-coordinate geometry to eight Mn and twelve Ga atoms. There are four shorter (3.17 Å) and four longer (3.36 Å) Ho–Mn bond lengths. There are eight shorter (3.23 Å) and four longer (3.41 Å) Ho–Ga bond lengths. There are two inequivalent Mn sites. In the first Mn site, Mn is bonded in a 12-coordinate geometry to two equivalent Ho, six Mn, and four equivalent Ga atoms. There are two shorter (2.41 Å) and four longer (2.69 Å) Mn–Mn bond lengths. All Mn–Ga bond lengths are 2.47 Å. In the second Mn site, Mn is bonded in a 10-coordinate geometry to one Ho, seven Mn, and six Ga atoms. There are a spread of Mn–Mn bond distances ranging from 2.61–3.08 Å. There are a spread of Mn–Ga bond distances ranging from 2.57–2.76 Å. There are two inequivalent Ga sites. In the first Ga site, Ga is bonded to two equivalent Ho, four equivalent Mn, and six Ga atoms to form a mixture of distorted face and corner-sharing GaHo2Mn4Ga6 cuboctahedra. There are two shorter (2.41 Å) and four longer (2.62 Å) Ga–Ga bond lengths. In the second Ga site, Ga is bonded in a 12-coordinate geometry to two equivalent Ho, six Mn, and two equivalent Ga atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho(Fe5Si)2 by Materials Project

HoFe10Si2 crystallizes in the orthorhombic Immm space group. The structure is three-dimensional. Ho is bonded in a 12-coordinate geometry to sixteen Fe and four equivalent Si atoms. There are a spread of Ho–Fe bond distances ranging from 2.93–3.18 Å. All Ho–Si bond lengths are 3.09 Å. There are four inequivalent Fe sites. In the first Fe site, Fe is bonded in a 10-coordinate geometry to one Ho, eleven Fe, and two equivalent Si atoms. There are a spread of Fe–Fe bond distances ranging from 2.33–2.91 Å. Both Fe–Si bond lengths are 2.60 Å. In the second Fe site, Fe is bonded in a 10-coordinate geometry to one Ho, eleven Fe, and two equivalent Si atoms. There are a spread of Fe–Fe bond distances ranging from 2.41–2.67 Å. Both Fe–Si bond lengths are 2.53 Å. In the third Fe site, Fe is bonded in a 12-coordinate geometry to two equivalent Ho, eight Fe, and two equivalent Si atoms. All Fe–Fe bond lengths are 2.44 Å. Both Fe–Si bond lengths are 2.61 Å. In the fourth Fe site, Fe is bonded to two equivalent Ho, eight Fe, and two equivalent Si atoms to form distorted FeHo2Fe8Si2 cuboctahedra that share corners with four equivalent SiHo2Fe10 cuboctahedra, corners with ten equivalent FeHo2Fe8Si2 cuboctahedra, edges with two equivalent SiHo2Fe10 cuboctahedra, edges with four equivalent FeHo2Fe8Si2 cuboctahedra, faces with four equivalent SiHo2Fe10 cuboctahedra, and faces with six equivalent FeHo2Fe8Si2 cuboctahedra. Both Fe–Fe bond lengths are 2.38 Å. Both Fe–Si bond lengths are 2.39 Å. Si is bonded to two equivalent Ho and ten Fe atoms to form distorted SiHo2Fe10 cuboctahedra that share corners with six equivalent SiHo2Fe10 cuboctahedra, corners with eight equivalent FeHo2Fe8Si2 cuboctahedra, edges with three equivalent SiHo2Fe10 cuboctahedra, edges with four equivalent FeHo2Fe8Si2 cuboctahedra, a faceface with one SiHo2Fe10 cuboctahedra, and faces with eight equivalent FeHo2Fe8Si2 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho(AlFe)6 by Materials Project

HoFe6Al6 crystallizes in the orthorhombic Immm space group. The structure is three-dimensional. Ho is bonded in a 8-coordinate geometry to twelve Fe and eight Al atoms. There are four shorter (3.21 Å) and eight longer (3.28 Å) Ho–Fe bond lengths. There are a spread of Ho–Al bond distances ranging from 2.85–3.01 Å. There are two inequivalent Fe sites. In the first Fe site, Fe is bonded in a 12-coordinate geometry to two equivalent Ho, four Fe, and six Al atoms. All Fe–Fe bond lengths are 2.50 Å. There are two shorter (2.51 Å) and four longer (2.60 Å) Fe–Al bond lengths. In the second Fe site, Fe is bonded to two equivalent Ho, four equivalent Fe, and six Al atoms to form a mixture of distorted face, edge, and corner-sharing FeHo2Al6Fe4 cuboctahedra. There are two shorter (2.59 Å) and four longer (2.63 Å) Fe–Al bond lengths. There are three inequivalent Al sites. In the first Al site, Al is bonded in a 10-coordinate geometry to one Ho, six Fe, and three Al atoms. There are one shorter (2.65 Å) and two longer (2.83 Å) Al–Al bond lengths. In the second Al site, Al is bonded in a 8-coordinate geometry to one Ho, six Fe, and one Al atom. The Al–Al bond length is 2.78 Å. In the third Al site, Al is bonded in a 12-coordinate geometry to two equivalent Ho, six Fe, and two equivalent Al atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho(SiIr)2 by Materials Project

Ho(IrSi)2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. Ho is bonded in a 8-coordinate geometry to eight Ir and eight Si atoms. There are four shorter (3.13 Å) and four longer (3.25 Å) Ho–Ir bond lengths. There are four shorter (3.16 Å) and four longer (3.18 Å) Ho–Si bond lengths. There are two inequivalent Ir sites. In the first Ir site, Ir is bonded to four equivalent Ho and four equivalent Si atoms to form distorted IrHo4Si4 tetrahedra that share corners with twelve equivalent SiHo4Ir4 tetrahedra, edges with two equivalent SiHo4Ir4 tetrahedra, edges with four equivalent IrHo4Si4 tetrahedra, and faces with four equivalent IrHo4Si4 tetrahedra. All Ir–Si bond lengths are 2.43 Å. In the second Ir site, Ir is bonded in a 9-coordinate geometry to four equivalent Ho and five Si atoms. There are one shorter (2.37 Å) and four longer (2.42 Å) Ir–Si bond lengths. There are two inequivalent Si sites. In the first Si site, Si is bonded to four equivalent Ho and four equivalent Ir atoms to form distorted SiHo4Ir4 tetrahedra that share corners with twelve equivalent IrHo4Si4 tetrahedra, edges with two equivalent IrHo4Si4 tetrahedra, edges with four equivalent SiHo4Ir4 tetrahedra, and faces with four equivalent SiHo4Ir4 tetrahedra. In the second Si site, Si is bonded in a 9-coordinate geometry to four equivalent Ho and five Ir atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho(SiPt)2 by Materials Project

HoPt2Si2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. Ho is bonded in a 12-coordinate geometry to eight Pt and eight Si atoms. There are four shorter (3.20 Å) and four longer (3.26 Å) Ho–Pt bond lengths. There are four shorter (3.19 Å) and four longer (3.21 Å) Ho–Si bond lengths. There are two inequivalent Pt sites. In the first Pt site, Pt is bonded in a 9-coordinate geometry to four equivalent Ho and five Si atoms. There are one shorter (2.38 Å) and four longer (2.43 Å) Pt–Si bond lengths. In the second Pt site, Pt is bonded to four equivalent Ho and four equivalent Si atoms to form distorted PtHo4Si4 tetrahedra that share corners with twelve equivalent SiHo4Pt4 tetrahedra, edges with two equivalent SiHo4Pt4 tetrahedra, edges with four equivalent PtHo4Si4 tetrahedra, and faces with four equivalent PtHo4Si4 tetrahedra. All Pt–Si bond lengths are 2.48 Å. There are two inequivalent Si sites. In the first Si site, Si is bonded in a 9-coordinate geometry to four equivalent Ho and five Pt atoms. In the second Si site, Si is bonded to four equivalent Ho and four equivalent Pt atoms to form distorted SiHo4Pt4 tetrahedra that share corners with twelve equivalent PtHo4Si4 tetrahedra, edges with two equivalent PtHo4Si4 tetrahedra, edges with four equivalent SiHo4Pt4 tetrahedra, and faces with four equivalent SiHo4Pt4 tetrahedra.

36 MATERIALS SCIENCE↗
NASA NTRS1986

Tropospheric HO determination by FAGE

In the detection of tropospheric HO by laser excited fluorescence, and alternative air-sampling method, named FAGE (Fluorescence Assay with Gas Expansion) was introduced. Here the air is expanded through a nozzle prior to excitation, in order to improve the ratio of the HO signal to the scattered, fluorescent, and photolytic backgrounds. The improvement comes from the differing pressure dependence of the intensities of these four terms, as well as the distinguishability of their temporal waveforms at low pressures when excited by a pulsed laser. HO has been excited by a YAG/dye laser. Other lasers and pumping paths may perform as well or better in this method. With FAGE, chemical modulation of the HO signal was achieved by hydrocarbon addition to the nozzle flow, converting photolytic HO from an interference to a background. Chemical calibration of the instrumental response to external HO was also achieved, by hydrocarbon decay, at HO concentrations within the ambient range.

Hard, T. M.↗
NASA NTRS2006

A Reevaluation of Airborne HO(x) Observations from NASA Field Campaigns

In-situ observations of tropospheric HO(x) (OH and HO2) obtained during four NASA airborne campaigns (SUCCESS, SONEX, PEM-Tropics B and TRACE-P) are reevaluated using the NASA Langley time-dependent photochemical box model. Special attention is given to previously diagnosed discrepancies between observed and predicted HO2 which increase with higher NO(x) levels and at high solar zenith angles. This analysis shows that much of the model discrepancy at high NO(x) during SUCCESS can be attributed to modeling observations at time-scales too long to capture the nonlinearity of HO(x) chemistry under highly variable conditions for NO(x). Discrepancies at high NO(x) during SONEX can be moderated to a large extent by complete use of all available precursor observations. Differences in kinetic rate coefficients and photolysis frequencies available for previous studies versus current recommendations also explain some of the disparity. Each of these causes is shown to exert greater influence with increasing NO(x) due to both the chemical nonlinearity between HO(x) and NO(x) and the increased sensitivity of HO(x) to changes in sources at high NO(x). In contrast, discrepancies at high solar zenith angles will persist until an adequate nighttime source of HO(x) can be identified. It is important to note that this analysis falls short of fully eliminating the issue of discrepancies between observed and predicted HO(x) for high NO(x) environments. These discrepancies are not resolved with the above causes in other data sets from ground-based field studies. Nevertheless, these results highlight important considerations in the application of box models to observationally based predictions of HO(x) radicals.

Olson, Jennifer↗
NASA NTRS2009

Single Longitudinal Mode, High Repetition Rate, Q-switched Ho:YLF Laser for Remote Sensing

Ho:YLF/LuLiF lasers have specific applications for remote sensing such as wind-speed measurement and carbon dioxide (CO2) concentration measurement in the atmosphere because the operating wavelength (around 2 m) is located in the eye-safe range and can be tuned to the characteristic lines of CO2 absorption and there is strong backward scattering signal from aerosol (Mie scattering). Experimentally, a diode pumped Ho:Tm:YLF laser has been successfully used as the transmitter of coherent differential absorption lidar for the measurement of with a repetition rate of 5 Hz and pulse energy of 75 mJ [1]. For highly precise CO2 measurements with coherent detection technique, a laser with high repetition rate is required to averaging out the speckle effect [2]. In addition, laser efficiency is critically important for the air/space borne lidar applications, because of the limited power supply. A diode pumped Ho:Tm:YLF laser is difficult to efficiently operate in high repetition rate due to the large heat loading and up-conversion. However, a Tm:fiber laser pumped Ho:YLF laser with low heat loading can be operated at high repetition rates efficiently [3]. No matter whether wind-speed or carbon dioxide (CO2) concentration measurement is the goal, a Ho:YLF/LuLiF laser as the transmitter should operate in a single longitudinal mode. Injection seeding is a valid technique for a Q-switched laser to obtain single longitudinal mode operation. In this paper, we will report the new results for a single longitudinal mode, high repetition rate, Q-switched Ho:YLF laser. In order to avoid spectral hole burning and make injection seeding easier, a four mirror ring cavity is designed for single longitudinal mode, high repetition rate Q-switched Ho:YLF laser. The ramp-fire technique is chosen for injection seeding.

Bai, Yingxin↗
NASA NTRS2016

An Efficient Single Frequency Ho:YLF Laser for IPDA Lidar Applications

A highly efficient, versatile, single frequency 2-micron pulsed laser can be used in a pulsed Differential Absorption Lidar (DIAL) / Integrated Path Differential Absorption (IPDA) instrument to make precise, high-resolution measurements to investigate sources and sinks of CO2. For a direct detection IPDA lidar, the desired 2 m Ho:YLF laser should generate 30-40 mJ pulses at the repetition rate of 100 to 200 Hz, with short pulse length (<100 ns) and better than 2% wall plug efficiency. A Tm fiber laser in-band pumped Ho:YLF laser has been developed to meet this technical challenge. This Ho:YLF laser is designed in a four mirror ring resonator with bow tie configuration, which helps to obtain high beam quality. It is end-pumped by a 40 W linearly polarized Tm fiber laser at 1.94μm. The resonator length is 1.10 meters with output coupler reflectivity at 45%. The laser crystal size is 3 x 3 x 60 mm (w, h, l) with a doping concentration of 0.5% Holmium. The laser beam and pump beam are mode-matched in the active medium. Thus, the pump and laser beams have the same confocal parameters. Mode-matching is also helpful for operating the laser in a single transverse mode. The laser beam waist is slightly less than 0.5 mm at the center of the laser crystal. Based on quasi-four level modeling, pump absorption and saturation depend on laser intensity. Laser amplification and saturation also depend on the pump intensity in the crystal. The laser is injection seeded to obtain the single frequency required by an IPDA lidar measurement. The seed beam is entered into the resonator through an output coupler. The laser is mounted on a water cooled optical bench for stable and reliable operation. The size of the optical bench is 22.16 x 9.20 x 1.25 inches. It is stiffened so that the laser can be operated in any orientation of the optical bench. This packaged Ho:YLF laser is designed for either mobile trailer or airborne platform operation. The engineering prototype Ho:YLF laser has been fully characterized to demonstrate laser performance. Figure 1 shows the laser output power as a function of pump power at different pulse repetition rates from 100 Hz to 333 Hz. The threshold of the laser is less than 14 W. The slope efficiencies are 28%, 40%, 41% and 43% for pulse repetition rates of 100, 200, 250 and 333 Hz, respectively. Maximum power increases with the pulse repetition rate. Output power of 4.2 W, 6 W, 6.7 W, and 7.7 W is achieved for pulse repetition rates of 100, 200, 250 and 333Hz, respectively. This represents the optical conversion efficiency of 16.7%, 22.4%, 23.7%, and 26.5% at these various pulse repletion rates. It is the most efficient and compact Ho:YLF laser demonstrated in the high pulse energy (>20mJ) and moderate pulse repetition rate (100's Hz) operation range. As shown in Figure 1, the maximum pulse energy at 100 Hz is 42 mJ. This is limited due to optical damage. The laser stability is characterized and found to be very stable. A relative pulse energy standard deviation of 2% was measured. The beam quality of the Ho:YLF was measured by a Spiricon infrared laser beam camera. Figure 2 shows the beam profile image of the laser. Both the X-profile of the beam (horizontal direction) and the Y-profile of the beam (vertical direction) are well fitted by a Gaussian profile. The qualitative beam quality measurement shows excellent beam quality in both axis. The M-square value for the laser beam is measured at 1.06 and 1.09 for the x and y axis respectively.-

Yu, J.↗
DOE OSTI2020

Materials Data on Ho(Al2Fe)4 by Materials Project

HoFe4Al8 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ho is bonded in a 12-coordinate geometry to eight equivalent Fe and twelve Al atoms. All Ho–Fe bond lengths are 3.32 Å. There are four shorter (2.95 Å) and eight longer (3.16 Å) Ho–Al bond lengths. Fe is bonded in a 12-coordinate geometry to two equivalent Ho, two equivalent Fe, and eight Al atoms. Both Fe–Fe bond lengths are 2.51 Å. There are four shorter (2.52 Å) and four longer (2.63 Å) Fe–Al bond lengths. There are two inequivalent Al sites. In the first Al site, Al is bonded in a 10-coordinate geometry to one Ho, four equivalent Fe, and five Al atoms. There are a spread of Al–Al bond distances ranging from 2.72–2.80 Å. In the second Al site, Al is bonded in a 12-coordinate geometry to two equivalent Ho, four equivalent Fe, and six Al atoms. Both Al–Al bond lengths are 2.71 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho(GeRu)2 by Materials Project

Ho(RuGe)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ho is bonded in a 8-coordinate geometry to eight equivalent Ru and eight equivalent Ge atoms. All Ho–Ru bond lengths are 3.26 Å. All Ho–Ge bond lengths are 3.28 Å. Ru is bonded in a 4-coordinate geometry to four equivalent Ho and four equivalent Ge atoms. All Ru–Ge bond lengths are 2.44 Å. Ge is bonded in a 9-coordinate geometry to four equivalent Ho, four equivalent Ru, and one Ge atom. The Ge–Ge bond length is 2.56 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho(PRu)2 by Materials Project

Ho(RuP)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ho is bonded in a 8-coordinate geometry to eight equivalent Ru and eight equivalent P atoms. All Ho–Ru bond lengths are 3.13 Å. All Ho–P bond lengths are 3.10 Å. Ru is bonded in a 12-coordinate geometry to four equivalent Ho and four equivalent P atoms. All Ru–P bond lengths are 2.35 Å. P is bonded in a 9-coordinate geometry to four equivalent Ho, four equivalent Ru, and one P atom. The P–P bond length is 2.38 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho(SiIr)2 by Materials Project

Ho(IrSi)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ho is bonded in a 8-coordinate geometry to eight equivalent Ir and eight equivalent Si atoms. All Ho–Ir bond lengths are 3.22 Å. All Ho–Si bond lengths are 3.13 Å. Ir is bonded to four equivalent Ho and four equivalent Si atoms to form a mixture of distorted edge, corner, and face-sharing IrHo4Si4 tetrahedra. All Ir–Si bond lengths are 2.41 Å. Si is bonded in a 9-coordinate geometry to four equivalent Ho, four equivalent Ir, and one Si atom. The Si–Si bond length is 2.41 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho(GeRh)2 by Materials Project

Ho(RhGe)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ho is bonded in a 8-coordinate geometry to eight equivalent Rh and eight equivalent Ge atoms. All Ho–Rh bond lengths are 3.31 Å. All Ho–Ge bond lengths are 3.19 Å. Rh is bonded to four equivalent Ho and four equivalent Ge atoms to form a mixture of distorted corner, edge, and face-sharing RhHo4Ge4 tetrahedra. All Rh–Ge bond lengths are 2.46 Å. Ge is bonded in a 9-coordinate geometry to four equivalent Ho, four equivalent Rh, and one Ge atom. The Ge–Ge bond length is 2.51 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho(FeB)2 by Materials Project

Ho(FeB)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ho is bonded in a 8-coordinate geometry to eight equivalent Fe and eight equivalent B atoms. All Ho–Fe bond lengths are 2.94 Å. All Ho–B bond lengths are 2.94 Å. Fe is bonded in a 4-coordinate geometry to four equivalent Ho and four equivalent B atoms. All Fe–B bond lengths are 2.00 Å. B is bonded in a 4-coordinate geometry to four equivalent Ho and four equivalent Fe atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho(ClO4)3 by Materials Project

Ho(O4Cl)3 crystallizes in the trigonal R3c space group. The structure is three-dimensional. Ho is bonded in a 9-coordinate geometry to nine O atoms. There are a spread of Ho–O bond distances ranging from 2.35–2.47 Å. There are four inequivalent O sites. In the first O site, O is bonded in a water-like geometry to one Ho and one Cl atom. The O–Cl bond length is 1.48 Å. In the second O site, O is bonded in a bent 150 degrees geometry to one Ho and one Cl atom. The O–Cl bond length is 1.47 Å. In the third O site, O is bonded in a single-bond geometry to one Cl atom. The O–Cl bond length is 1.42 Å. In the fourth O site, O is bonded in a water-like geometry to one Ho and one Cl atom. The O–Cl bond length is 1.48 Å. Cl is bonded in a tetrahedral geometry to four O atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho(BRh)4 by Materials Project

Ho(RhB)4 crystallizes in the tetragonal P4_2/nmc space group. The structure is three-dimensional. Ho is bonded in a 12-coordinate geometry to twelve equivalent Rh and twelve equivalent B atoms. There are four shorter (2.96 Å) and eight longer (3.17 Å) Ho–Rh bond lengths. There are eight shorter (3.03 Å) and four longer (3.14 Å) Ho–B bond lengths. Rh is bonded in a 5-coordinate geometry to three equivalent Ho and five equivalent B atoms. There are a spread of Rh–B bond distances ranging from 2.21–2.24 Å. B is bonded in a 6-coordinate geometry to three equivalent Ho, five equivalent Rh, and one B atom. The B–B bond length is 1.81 Å.

36 MATERIALS SCIENCE↗