Subject: Obtaining lowest 20% of eigenstates

From: Andrew Horsfield <[email-masked]>
Date: Thu, 12 Aug 1999 09:09:46 +0100 (BST)

Together with colleagues at the Unversity of Oxford, I am developing an
LCAO DFT code that handles solids as well as molecules. It makes use of
numerical orbitals (somewhat akin to DMol3). For a cell containing 64
atoms of silicon with a DZP basis set (sp s*p* d), and using 4 kpoints,
95% of the time is spent on diagonalising the Hamiltonian (lapack is being
used). Clearly a scheme that only generates the first few eigenstates
(20%) is needed to reduce this time. What would people recommend?  
Contenders that I have encountered so far are Arpack and Lapack 3.

Best regards,

Andrew

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