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 should be the partially optimized
# coordinates (or the fully optimized coordinates would work too). The next
# input for ADF shows how to perform a frequency calculation with MBH. The flag
# b=b1 in the ATOMS section adds the label 'b1' to some of the atoms. Only the
# four atoms labeled 'b1' (CH3 ) will be considered as a block with fixed
# internal geometry.



$ADFBIN/adf <<eor
TITLE ethanol: second derivatives with MBH approach. CH3 is treated as a rigid block

ATOMS
1 C      -0.029587   -0.006554    0.008124     b=b1 
2 H      -0.087498   -0.025163    1.109913     b=b1
3 H       1.027473   -0.056237   -0.302751     b=b1
4 H      -0.565305   -0.891154   -0.376242     b=b1
5 C      -0.694908    1.238909   -0.501807     b=b2
6 H      -0.670258    1.265092   -1.608847     b=b2
7 O      -2.069894    1.175059   -0.017251
8 H      -0.182335    2.138977   -0.109315     b=b2
9 H      -2.586972    1.972802   -0.317216
END

SYMMETRY nosym

BASIS
  type DZ
  core Large
  CreateOutput None
END

XC
LDA SCF VWN
END

SCF
  Converge 1.0e-8
END
GEOMETRY
   frequencies
   End
   mbh b1
END

NumericalQuality good
eor

mv TAPE21 Ethanol_MBH.t21


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


$ADFBIN/adf <<eor
TITLE ethanol: complete vibrational spectrum, compare with MBH above

ATOMS
1 C      -0.029587   -0.006554    0.008124
2 H      -0.087498   -0.025163    1.109913
3 H       1.027473   -0.056237   -0.302751
4 H      -0.565305   -0.891154   -0.376242
5 C      -0.694908    1.238909   -0.501807
6 H      -0.670258    1.265092   -1.608847
7 O      -2.069894    1.175059   -0.017251
8 H      -0.182335    2.138977   -0.109315
9 H      -2.586972    1.972802   -0.317216
END

BASIS
  type DZ
  core Large
  CreateOutput None
END

XC
LDA SCF VWN
END

AnalyticalFreq
End

NumericalQuality good
eor

mv TAPE21 Ethanol_full.t21