Example: Mobile Block Hessian (MBH): Ethanol¶

Download MBH_Ethanol.run

#! /bin/sh


# A frequency calculation is performed using the mobile block Hessian (MBH)
# method. The coordinates in the ATOMS section can be the partially optimized
# coordinates (or the fully optimized coordinates would work too).


AMS_JOBNAME=Ethanol_MBH $AMSBIN/ams <<eor
System
  atoms
     C      -0.029587   -0.006554    0.008124
     H      -0.087498   -0.025163    1.109913
     H       1.027473   -0.056237   -0.302751
     H      -0.565305   -0.891154   -0.376242
     C      -0.694908    1.238909   -0.501807
     H      -0.670258    1.265092   -1.608847
     O      -2.069894    1.175059   -0.017251
     H      -0.182335    2.138977   -0.109315
     H      -2.586972    1.972802   -0.317216
  end
end

Task SinglePoint
Properties
    NormalModes True
End
NormalModes
    Displacements Block
    BlockDisplacements
        BlockAtoms 1 2 3 4
    End
End


Engine ADF
  title ethanol: second derivatives with MBH approach. CH3 is treated as a rigid block
  numericalquality good
  scf
    converge 1.0e-8
  end
  symmetry nosym
EndEngine
eor


# For comparison in this example also a calculation is performed without any
# restrictions.


AMS_JOBNAME=Ethanol_full $AMSBIN/ams <<eor
System
  atoms
     C      -0.029587   -0.006554    0.008124
     H      -0.087498   -0.025163    1.109913
     H       1.027473   -0.056237   -0.302751
     H      -0.565305   -0.891154   -0.376242
     C      -0.694908    1.238909   -0.501807
     H      -0.670258    1.265092   -1.608847
     O      -2.069894    1.175059   -0.017251
     H      -0.182335    2.138977   -0.109315
     H      -2.586972    1.972802   -0.317216
  end
end

Task SinglePoint
Properties
    NormalModes True
End

Engine ADF
  title ethanol: complete vibrational spectrum, compare with MBH above
  numericalquality good
EndEngine
eor