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Methane: Non-polarisable Isotropic model
Summary:
- ISA charge model for electrostatics. No damping.
$C_{6}$, isotropic damped dispersion model.
- Isotropic exchange-repulsion terms only.
Units: Atomic Units
Citations
A. J. Misquitta & A. J. Stone, //Ab initio atom–atom potentials using CamCASP: Theory//
Geometry and charges
Source: BS-ISA, A+DF $\zeta=0.1$ aug-cc-pVTZ main basis with aQZ/set2 aux basis. PBE0/AC. CamCASP 5.8.
<code | CH4-ISA.mom> ! Based on DF-type : ISA C 0.00000000 0.00000000 0.00000000 Type C Rank 0 -0.413530 H1 0.00000000 2.07703578 0.00000000 Type H Rank 0 0.103598 H2 1.69589261 -0.69234525 0.97912406 Type H Rank 0 0.103383 H3 -1.69589261 -0.69234525 0.97912406 Type H Rank 0 0.103383 H4 0.00000000 -0.69234525 -1.95824810 Type H Rank 0 0.103166
Potential & Damping
Coefficients fitted using Orient. Tang-Toennies damping. Single dispersion damping coefficient.
<code| CH4-iso-nonpol.pot> C C rho alpha 00 00 0 6.386635 1.821348 END C H rho alpha 00 00 0 4.839902 1.707686 END H H rho alpha 00 00 0 4.263985 1.610924 END Dispersion damping Factor 1.93 ! Dispersion C C rho alpha C6 00 00 0 5.552955 2.179220 22.07923 END C H rho alpha C6 00 00 0 4.186650 1.898729 10.09522 END H H rho alpha C6 00 00 0 4.782582 1.647922 4.87260 END
Sample Orient command file
You will need the above files present in the directory as they are included into this Orient file.
Orient version: 4.7/4.8
<code | CH4_2-iso-scaled.ornt> UNITS BOHR Parameters Sites 100 polarizable 100 S-functions 50000 Alphas 50000 Parameter-sets 50000 Pairs 100000 Molecules 10 End Types C Z 6 H Z 1 End Variables Rx 10.0 B Ry 0.0 B Rz 0.0 B alpha 0.0 D Nx 0.0 Ny 0.0 Nz 1.0 Index 0 End Molecule CH4_A at 0 0 0 rotated by 0 about 0 0 1 #include CH4-ISA.mom End Molecule CH4_B at Rx Ry Rz rotated by alpha about Nx Ny Nz #include CH4-ISA.mom End Pairs #include ./CH4-iso-scaled.pot End Units Bohr kJ/mol Comment "Energy calculation" Energy Table Format e15.7 Print es er ind disp total Variables Index Rx Ry Rz alpha Nx Ny Nz 2 0.00 -4.20 0.00 180 1.000 0.000 0.000 3 0.00 -4.90 0.00 180 1.000 0.000 0.000 4 0.00 -5.60 0.00 180 1.000 0.000 0.000 5 0.00 -6.30 0.00 180 1.000 0.000 0.000 6 0.00 -6.65 0.00 180 1.000 0.000 0.000 7 0.00 -7.00 0.00 180 1.000 0.000 0.000 8 0.00 -7.35 0.00 180 1.000 0.000 0.000 9 0.00 -7.70 0.00 180 1.000 0.000 0.000 10 0.00 -8.40 0.00 180 1.000 0.000 0.000 11 0.00 -9.10 0.00 180 1.000 0.000 0.000 12 0.00 -9.80 0.00 180 1.000 0.000 0.000 End Finish
Output should end with
<code | end of output> Rx Ry Rz alpha Nx Ny Nz Index es er ind disp total 2.00000 0.00000 -4.20000 0.00000 180.00000 1.00000 0.00000 0.00000 1.852709 270.249369 0.000000 -60.450602 211.651476 3.00000 0.00000 -4.90000 0.00000 180.00000 1.00000 0.00000 0.00000 0.856593 86.771411 0.000000 -30.904873 56.723131 4.00000 0.00000 -5.60000 0.00000 180.00000 1.00000 0.00000 0.00000 0.419628 27.751366 0.000000 -15.948023 12.222972 5.00000 0.00000 -6.30000 0.00000 180.00000 1.00000 0.00000 0.00000 0.216730 8.853454 0.000000 -8.440580 0.629604 6.00000 0.00000 -6.65000 0.00000 180.00000 1.00000 0.00000 0.00000 0.158628 4.997924 0.000000 -6.218482 -1.061929 7.00000 0.00000 -7.00000 0.00000 180.00000 1.00000 0.00000 0.00000 0.117429 2.820846 0.000000 -4.624501 -1.686225 8.00000 0.00000 -7.35000 0.00000 180.00000 1.00000 0.00000 0.00000 0.087870 1.591933 0.000000 -3.472697 -1.792894 9.00000 0.00000 -7.70000 0.00000 180.00000 1.00000 0.00000 0.00000 0.066424 0.898381 0.000000 -2.633554 -1.668749 10.00000 0.00000 -8.40000 0.00000 180.00000 1.00000 0.00000 0.00000 0.039048 0.286164 0.000000 -1.559318 -1.234106 11.00000 0.00000 -9.10000 0.00000 180.00000 1.00000 0.00000 0.00000 0.023758 0.091203 0.000000 -0.958023 -0.843061 12.00000 0.00000 -9.80000 0.00000 180.00000 1.00000 0.00000 0.00000 0.014907 0.029091 0.000000 -0.608855 -0.564857