Use Gaussian or WebMO to calculate the Electron Affinity of Helium、Neon、Argon, by using B3LYP、MP2 and M062X theoretical methods with cc-pVTZ、aug-cc-pVTZ、d-aug-cc-pVTZ basis set, and do some simple statistical analysis.(check your unit、analysis tools)
(unit : hartree)
| 中性 | B3LYP | cc-pVTZ | aug-cc-pVTZ | d-aug-cc-pVTZ |
| He | -2.91451 | -2.91469 | -2.91469 | |
| Ne | -128.96186 | -128.96629 | -128.96629 | |
| Ar | -527.55937 | -527.56000 | ||
| MP2 | cc-pVTZ | aug-cc-pVTZ | d-aug-cc-pVTZ | |
| He | -2.89429 | -2.89480 | -2.89482 | |
| Ne | -128.79618 | -128.80579 | -128.80635 | |
| Ar | -527.01904 | -527.02428 | ||
| M062X | cc-pVTZ | aug-cc-pVTZ | d-aug-cc-pVTZ | |
| He | -2.90399 | -2.90410 | -2.90410 | |
| Ne | -128.92656 | -128.92926 | -128.92926 | |
| Ar | -527.53220 | -527.53259 |
(unit : hartree)
| 陰離子 | B3LYP | cc-pVTZ | aug-cc-pVTZ | d-aug-cc-pVTZ |
| He | -2.31407 | -2.81612 | -2.89858 | |
| Ne | -127.95793 | -128.75875 | -128.92100 | |
| Ar | -527.07695 | -527.44495 | ||
| MP2 | cc-pVTZ | aug-cc-pVTZ | d-aug-cc-pVTZ | |
| He | -2.26566 | -2.78588 | -2.87381 | |
| Ne | -127.72531 | -128.58062 | -128.75311 | |
| Ar | -526.49200 | -526.90027 | ||
| M062X | cc-pVTZ | aug-cc-pVTZ | d-aug-cc-pVTZ | |
| He | -2.31852 | -2.80420 | -2.88709 | |
| Ne | -127.91524 | -128.71941 | -128.87856 | |
| Ar | -527.05240 | -527.41652 |
(unit : kcal/mol)
| electron affinity | B3LYP | cc-pVTZ | aug-cc-pVTZ | d-aug-cc-pVTZ | Exp |
| He | 376.8 | 61.9 | 10.1 | 11.53 | |
| Ne | 630.0 | 130.2 | 28.4 | 27.67 | |
| Ar | 302.7 | 72.2 | 23.06 | ||
| MP2 | cc-pVTZ | aug-cc-pVTZ | d-aug-cc-pVTZ | Exp | |
| He | 394.5 | 68.3 | 13.2 | 11.53 | |
| Ne | 672.0 | 141.3 | 33.4 | 27.67 | |
| Ar | 330.7 | 77.8 | 23.06 | ||
| M062X | cc-pVTZ | aug-cc-pVTZ | d-aug-cc-pVTZ | Exp | |
| He | 367.4 | 62.7 | 10.67160381 | 11.53 | |
| Ne | 634.6 | 131.7 | 31.81773012 | 27.67 | |
| Ar | 301.1 | 72.8 | 23.06 |
(unit : kcal/mol)
| absolute error | B3LYP | B3LYP/cc-pVTZ | B3LYP/aug-cc-pVTZ | B3LYP/d-aug-cc-pVTZ |
| He | 365.2 | 61.9 | 10.1 | |
| Ne | 602.3 | 102.6 | 0.7 | |
| Ar | 279.7 | 49.1 | ||
| MP2 | MP2/cc-pVTZ | MP2/aug-cc-pVTZ | MP2/d-aug-cc-pVTZ | |
| He | 382.9 | 56.8 | 1.7 | |
| Ne | 644.3 | 113.6 | 5.7 | |
| Ar | 307.7 | 54.8 | ||
| M062X | M062X/cc-pVTZ | M062X/aug-cc-pVTZ | M062X/d-aug-cc-pVTZ | |
| He | 355.9 | 51.2 | 0.9 | |
| Ne | 606.9 | 104.0 | 4.1 | |
| Ar | 278.0 | 49.8 |
結論:使用三種理論方法的計算結果沒有太大的變化，而使用更大的基底函數會使計算結果更靠近實驗值。
Try to add an additional set of diffuse functions for the s orbital of He, and the s and p orbitals of Ne and Ar. ( in the 6-31G basis set )
| electron affinity | (unit : kcal/mol) | |||
| B3LYP | 6-31G | 6-31G(+diffuse) | 6-31G(+2diffuse) | Exp |
| He | 829.86 | 144.35 | 57.76 | 11.53 |
| Ne | 1009.36 | 181.94 | 84.17 | 27.67 |
| Ar | 343.52 | 61.34 | 28.03 | 23.06 |
| MP2 | 6-31G | 6-31G(+diffuse) | 6-31G(+2diffuse) | Exp |
| He | 860.33 | 156.70 | 65.99 | 11.53 |
| Ne | 1080.89 | 203.33 | 96.71 | 27.67 |
| Ar | 382.08 | 75.22 | 36.08 | 23.06 |
| M062X | 6-31G | 6-31G(+diffuse) | 6-31G(+2diffuse) | Exp |
| He | 827.87 | 140.62 | 60.67 | 11.53 |
| Ne | 1011.24 | 186.59 | 85.59 | 27.67 |
| Ar | 341.34 | 61.96 | 29.15 | 23.06 |
結論:不管是使用哪種理論方法，增加 diffuse function會讓計算結果更靠近實驗值。
Try to use Gaussian or WebMO to optimize the H₃⁺ molecule and calculate the linear dissociation energy according to the formula provided in the PDF lecture.
| CISD/aug-cc-pVTZ | (hartree) | (kcal/mol) |
| H3+ | -1.32923 | -834.1 |
| H | -0.49982 | -313.6 |
| H2 | -1.14627 | -719.3 |
| H2+ | -0.60162 | -377.5 |
| dissociation energy | -0.08116 | -50.9 |