Molcas Forum

Andrey

Member

Registered: 2017-12-06

Posts: 1

Problem in QM/MM optimization

I have tried to perform QM/MM optimization in Molcas 7.8.
Here part of my slapaf input:

   &SLAPAF
    cartesian
    rHidden = 4.0

First start of optimization has successful ended, but on each step of slapaf it printed this warning:

###     Warning argument of aCos=  1.000000000000000222                     ###

When i have try to restart optimization from last point, it fail with next error

 #####################################
 #####################################
 ###                                                                         ###
 ###                                                                         ###
 ###    Abend in Strtch                                               ###
 ###                                                                         ###
 ###                                                                         ###
 #####################################
 #####################################
 ***************** ERROR **********************
  Short (or negative) distance for coordinate: 
          : Bond Length=  0.000000 / Angstrom  0.000000 / bohr
 **********************************************