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--- ncpchem:chiral_field [2025/04/22 18:53]
47.128.112.219 old revision restored (2025/04/09 08:32)
+++ ncpchem:chiral_field [2025/04/27 16:20] (current)
13.59.56.153 old revision restored (2025/04/26 17:10)
@@ Line 6: / Line 6: @@
 </WRAP>
 <WRAP column 500px>
-The CHFClBr equilibrium geometry, optimised at the .. level (taken from here), was scaled in the range 0.5 - 2.0 and the total and EPV energy
+The CHFClBr equilibrium geometry, optimised at the scalar relativistic CCSD(T) level (taken from [[http://link.aps.org/doi/10.1103/PhysRevA.65.042508|here]]), was scaled in the range 0.5 - 2.0 and the total and E<sub>PV</sub> energy
 was calculated at the B3LYP level.
 As pointed out by Peter the bond stretching will inevitably lead to a breakdown of the SCF model. Indeed one observes that the HOMO-LUMO gap closes
 and the SCF did not converge beyond scaling factor 1.4
+The CCSD(T) optimized geometry is:\\
+r(C<sub>1</sub>-Br): 1.976 Å\\
+r(C<sub>1</sub>-Cl): 1.776 Å\\
+r(C<sub>1</sub>-H):  1.100 Å\\
 </WRAP>
 </WRAP>
@@ Line 18: / Line 23: @@
 </WRAP>
 <WRAP column 500px>
-Nuclear repulsion energy
+The nuclear repulsion energy is evidently not affected by the breakdown of the wavefunction model and drops off as 1/s, where s is the scaling factor.
 </WRAP>
 </WRAP>
@@ Line 27: / Line 32: @@
 </WRAP>
 <WRAP column 500px>
-Total energy
+The total energy can be fitted to a 5th-order polynomial within the range of validity of the model and has, as expected, a minimum near the scaling factor 1.0.
+</WRAP>
+</WRAP>
+<WRAP box>
+<WRAP column 500px>
+{{:ncpchem:totalepv.jpg?490}}
+</WRAP>
+<WRAP column 500px>
+The total E<sub>PV</sub> energy is not the most interesting quantity since the change in the chiral field for all atoms except the central carbon atom is rather complicated.
 </WRAP>
 </WRAP>
@@ Line 36: / Line 52: @@
 </WRAP>
 <WRAP column 500px>
-Total energy
+More interesting is the contribution to the E<sub>PV</sub> energy from the central carbon atom. Surprisingly it increases within the range of validity of the model and goes through a minimum around s=0.82. It can be fitted well to a 4th-order polynomial.
 </WRAP>
 </WRAP>
 <WRAP box>
+<WRAP column 200px>
+{{:ncpchem:chfclbr.png?190}}
+</WRAP>
+<WRAP column 350px>
+<file CHFXopt.xyz>
+scf done: -3172.829144
+ C    -1.874368     1.699460    -0.238135
+Br    -2.517620    -0.079089     0.215619
+ H    -2.245107     1.932961    -1.232587
+Cl    -2.454927     2.930736     0.887073
+ F    -0.528269     1.693590    -0.245441
+</file>
+</WRAP>
 <WRAP column 500px>
-{{:ncpchem:totalepv.jpg?490}}
+r(C<sub>1</sub>-Br): 1.945 Å\\
+r(C<sub>1</sub>-Cl): 1.766 Å\\
+r(C<sub>1</sub>-H):  1.087 Å\\
+Total energy: -3206.489586 hartree\\
+HOMO-LUMO gap: 0.248490 hartree\\
+Total E<sub>PV</sub> = 1.001E-18 hartree\\
+E<sub>PV</sub> (central carbon C<sub>1</sub>): 5.523E-20 hartree\\
+</WRAP>
+</WRAP>
+<WRAP box>
+<WRAP column 200px>
+{{:ncpchem:cb_chfclbr.png?190}}
+</WRAP>
+<WRAP column 350px>
+<file cb_CHFX_Ropt.xyz>
+
+scf done: -3477.261538
+ C    -1.712432     1.322399    -0.468191  H
+ C    -2.083610    -0.032394    -0.003986  H
+ C    -2.498564     1.665678    -1.672890  H
+ C    -1.993900     2.307555     0.597662  H
+ C    -0.270315     1.354795    -0.798693  H
+ C    -3.139942     1.948107    -2.650403  H
+ C    -2.225567     3.109877     1.460851  H
+ C    -2.385463    -1.125021     0.370581  H
+ C     0.898869     1.383167    -1.067164  L H
+Cl    -2.539540     4.202586     2.638111  H
+ H     1.935810     1.408304    -1.305458  H
+Br    -4.092424     2.366916    -4.103780  H
+ F    -2.707154    -2.290764     0.770012  L H
+</file>
 </WRAP>
 <WRAP column 500px>
-Total EPV energy
+r(C<sub>1</sub>-Br): 4.469 Å\\
+r(C<sub>1</sub>-Cl): 4.316 Å\\
+r(C<sub>1</sub>-H):  3.744 Å\\
+Total energy: -3510.990470 hartree\\
+HOMO-LUMO gap: 0.242571 hartree\\
+Total E<sub>PV</sub> = 1.629E-20 hartree\\
+E<sub>PV</sub> (central carbon C<sub>1</sub>): 2.905E-23 hartree\\
+</WRAP>
+</WRAP>
+<WRAP box>
+<WRAP column 200px>
+{{:ncpchem:cb2_chfclbr.png?190}}
+</WRAP>
+<WRAP column 350px>
+<file cb2_CHFXopt.xyz>
+
+scf done: -3781.817398
+ C    -1.569422     1.426972    -0.444525  H
+ C    -1.877703     0.020308    -0.116740  H
+ C    -2.369353     1.848010    -1.612073  H
+ C    -1.896220     2.286398     0.710845  H
+ C    -0.132460     1.555677    -0.761518  H
+ C    -3.025886     2.193654    -2.567233  H
+ C    -2.164591     2.990875     1.656343  H
+ C    -2.131541    -1.129727     0.151315  H
+ C     1.043019     1.661785    -1.021021  L H
+ C    -2.466017     3.781276     2.718191  H
+ C     2.367315     1.781049    -1.313191  H
+ C    -3.763495     2.581033    -3.638934  H
+ C    -2.417583    -2.425916     0.453469  L H
+ C    -4.422240     2.926515    -4.595711  H
+ C    -2.733502     4.485859     3.664755  H
+ C     3.542557     1.886953    -1.572586  H
+ C    -2.670204    -3.569979     0.720249  H
+ H     4.577709     1.980457    -1.801197  H
+Cl    -3.094602     5.433954     4.939276  H
+Br    -5.390750     3.433046    -5.999501  H
+ F    -2.937158    -4.778650     1.002047  H
+</file>
+</WRAP>
+<WRAP column 500px>
+r(C<sub>1</sub>-Br): 7.035 Å\\
+r(C<sub>1</sub>-Cl): 6.882 Å\\
+r(C<sub>1</sub>-H):  6.319 Å\\
+Total energy: -3815.623118 hartree\\
+HOMO-LUMO gap: 0.198085 hartree\\
+Total E<sub>PV</sub> = -9.436E-23 hartree\\
+E<sub>PV</sub> (central carbon C<sub>1</sub>): -3.737E-25 hartree\\
 </WRAP>
 </WRAP>

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