RAMVIB: a new flexible normal mode analysis software package for biological spectroscopists

A new package of computer programs called RAMVIB and designed to perform normal mode calculations is described. In our experience, RAMVIB has been proven useful in theoretical interpretation of resonance Raman spectra of metalloprotein active sites and their model complexes. It differs from existing programs in many aspects. The new and powerful vibrational force field optimization technique used in RAMVIB is free of singularity and regularization error problems. An arbitrary subset of force constants can be refined simultaneously for any collection of related molecules. A set of diagnostic programs tests quality and condition of input matrices. A thorough force constant selection can be performed based on several independent criteria. Coordinate redundancies are automatically removed by our new algorithm. Similarly, normal modes for different isotopomers are sorted and matched automatically. The flexibility of RAMVIB coming from its modular character makes it easily adjustable to solve a number of other problems related to normal mode analysis, e.g. calculation of scaling factors of ab initio derived harmonic force fields. (C) 1997 Elsevier Science B.V.