First-principles calculation of LaNi₅surface

Abstract

Abstract. The spin-polarized, all-electron, ab initio calculations have been performed for the electronic structure of the surface of crystal LaNi 5 using the self-consistent cluster-embedding (SCCE) calculation method. The geometrical surface structure of crystal LaNi 5 and its electronic structure having the lowest ground-state energy are obtained, with the full relaxation of atomic positions along the direction perpendicular to the surface. On the surface of crystal LaNi 5 , the La atom protruded, and the Ni atoms caved in, so the surface becomes uneven which increases the contacting area. The effective volume of the surface layer rises by 9%. The Fermi level of the LaNi 5 surface, which is contributed by mainly Ni 3d electrons, is much higher than that of body LaNi 5 . The valence band is not fully filled. For the first two layers of LaNi 5 surface, there are 1.15 electrons transferred from La to Ni, and the two layers have small opposite spin magnetic moments which shows the paramagnet. All calculated results show that the properties of LaNi 5 surface are significantly different from that of body LaNi 5 , but very similar to that of hydride LaNi 5 H 7 . So the geometrical surface structure of crystal LaNi 5 is in favor of the absorption of hydrogen.

Equivalent potential of water molecules for electronic structure of glutamic acid

“…Based on the geometric structure of Glu − + 5H 2 O system determined in an earlier section, the system is now divided into six clusters for the “self‐consistent cluster‐embedding calculation (SCCE).” The Glu − molecule is the first cluster, and each water molecule is one cluster. The software of the SCCE calculation is developed by our group and has been applied to several insulators, semi‐conductors, metals, crystals with defects and impurities, surfaces, and proteins 2–12…”

“…This makes the electronic structure calculation of protein a reality. The SCCE calculations have been successfully applied to several insulators, semiconductors, metals, crystals with defects and impurities, and surfaces 2–8…”

The equivalent dipole potential of water for the electronic structure of threonine

“…The Thr is the first cluster, and each water molecule is one cluster. The software of the SCCE calculation is developed by our group and has been applied to several insulators, semiconductors, metals, crystals with defects and impurities, surfaces, and proteins [17][18][19][20][21][22][23][24][25][26][27].…”

“…So using the SCCE method, the localized valence electrons of real material can be better described, and the computational effort can be reduced greatly while the calculation accuracy is kept unchanged. The SCCE calculations have been successfully applied to several insulators, semiconductors, metals, crystals with defects and impurities, and surfaces [17][18][19][20][21][22][23]. Up to now, the electronic structures of three proteins with four three-dimensional structures have been obtained using the SCCE method [24][25][26][27].…”

Equivalent potential of water for electronic structure of asparagine

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