APPLICATION OF LOCALIZED MOLECULAR-ORBITALS TO THE SOLUTION OF SEMIEMPIRICAL SELF-CONSISTENT-FIELD EQUATIONS

When conventional matrix algebra is used to solve the semiempirical se lf-consistent field equations for large systems, the time required ris es as the third power of the size of the system A consequence of this is that self-consistent calculations of large systems such as enzymes ate impractical. By using localized molecular orbitals instead of matr ix methods, the time required for these systems can be made almost pro portional to the size of the system. In partial geometry optimizations , the time required depends only upon the size of the fragment being o ptimized and is almost independent of the size of the whole system. (C ) 1996 John Wiley & sons, Inc.