HvD: Modified the calculation of the COSMO charges: 1. The iterative linear system solver for Ax=b now starts with x from    the previous SCF cycle rather than x=0. 2. The sum of the COSMO charges x should be equal to the charge    contained within the surface. In practice you don't quite get that    and the COSMO charges are corrected for this. Previously the    correction was done by scaling the charges, but this causes problems    for neutral systems where the scale factor would be 0. A cumbersome    work around was implemented for that that required the COSMO charges    to be calculated multiple times per SCF cycle. The correction can    also be introduced by adding a correction. This does not lead to    formal problems and easily allows the COSMO charges to be calculated    with a single linear system solve. The difference between these    two approaches amounts to less than 0.3 kcal/mol in the solvation    energy. 3. The COSMO charges were computed serially. The matrix-vector     multiplication routines were trivially parallelized using a     replicated data approach.
HvD: Modified the calculation of the COSMO charges:
1. The iterative linear system solver for Ax=b now starts with x from
   the previous SCF cycle rather than x=0.
2. The sum of the COSMO charges x should be equal to the charge
   contained within the surface. In practice you don't quite get that
   and the COSMO charges are corrected for this. Previously the
   correction was done by scaling the charges, but this causes problems
   for neutral systems where the scale factor would be 0. A cumbersome
   work around was implemented for that that required the COSMO charges
   to be calculated multiple times per SCF cycle. The correction can
   also be introduced by adding a correction. This does not lead to
   formal problems and easily allows the COSMO charges to be calculated
   with a single linear system solve. The difference between these
   two approaches amounts to less than 0.3 kcal/mol in the solvation
   energy.
3. The COSMO charges were computed serially. The matrix-vector 
   multiplication routines were trivially parallelized using a 
   replicated data approach.





rangsimanketkaew/NWChem