Speedup techniques in quasi-cannonical localized orbitals calculation for all-electron computation on proteins

Abstract

To understand electronic properties and reactivities of proteins, we have developed a gaussian-based density functional program, ProteinDF. In fact, an all-electron wavefunction of hemoprotein cytochrome c was calculated by this program. It is necessary for all-electron calculations on proteins to find any method estimating a good initial guess. We developed the quasi-cannonical localized orbital method which creates accurate initial MOs of elongated peptide chain from MOs of small peptides. However, the calculation of the quasi-cannonical localized orbitals is proportional to the 4th power of the number of basis functions. In this study, we accelerated this calculation.