Hello,
I am running NMR shielding calculations. The output looks like:
Atom: 1 P
Diamagnetic
1001.3545 -0.0000 0.0000
-0.0000 1001.3545 0.0000
0.0000 0.0000 997.8388
Paramagnetic
-782.7759 -0.0075 -0.0031
-0.0075 -782.7970 0.0003
-0.0031 0.0003 -558.6973
Total Shielding Tensor
218.5786 -0.0075 -0.0031
-0.0075 218.5575 0.0004
-0.0031 0.0004 439.1416
isotropic = 292.0926
anisotropy = 220.5735
Principal Components and Axis System
1 2 3
439.1416 218.5810 218.5551
1 -0.0000 0.9525 0.3044
2 0.0000 -0.3044 0.9525
3 1.0000 0.0000 0.0000
and this
Atom: 1 P
Diamagnetic
996.2680 -3.5903 0.0000
-3.5903 998.4667 -0.0000
0.0000 -0.0000 992.8941
Paramagnetic
-764.7397 70.9300 -0.0000
70.9300 -786.0511 0.0000
-0.0000 0.0000 -653.5802
Total Shielding Tensor
231.5284 67.3396 -0.0000
67.3396 212.4157 0.0000
-0.0000 0.0000 339.3139
isotropic = 261.0860
anisotropy = 117.3419
Principal Components and Axis System
1 2 3
339.3139 289.9864 153.9577
1 0.0000 0.7552 -0.6556
2 0.0000 0.6556 0.7552
3 1.0000 -0.0000 -0.0000
I am attempting to measure the chemical shift difference between H3PO4 and HPO4(2-).
I assume that I should use the "Total Shielding Tensor" part, but which of the numbers should I use to find the difference in observed chemical shift between the two molecules?
Thanks,
-DC
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