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A New Technique for the Evaluation of Densities of States in ab initio Calculations of Periodic Systems
Author(s) -
Angonoa Giuliana,
Dovesi R.,
Pisani C.,
Roetti Carla
Publication year - 1984
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2221220125
Subject(s) - legendre polynomials , ab initio , beryllium , density of states , statistical physics , materials science , physics , quantum mechanics , nuclear physics
A recently introduced expansion technique for calculating densities of states (DOS) of crystalline systems is applied for the first time in conjunction with ab initio HF calculations. Graphite, lithium, and beryllium are chosen as test systems; Legendre polynomials are used as the orthogonal expansion set. The quality of the results depends both on the density of the sampling net used for the evaluation of the expansion coefficients, and on the number of terms used in the expansion; the influence of these two parameters is discussed. It is shown that the new technique provides a substantially accurate description of the DOS and related quantities (Fermi energy, density matrix), although it is not able to reveal the fine structure of the spectrum. The computing time is about ten times less than required by conventional techniques of comparable accuracy.