The ab initio calculation for Li2F and Na2F systems |
| Yue Wang, Bi Lv Fang, Yu Liu, De Zhi Dong, Gan Gan, Cheng Wen Zhang
Department of Electrical Engineering, Tongling University, 1335 Cuihu 4th Road, 244000, Tongling, China |
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| The globally accurate potential energy surface for the ground state of Li2F and Na2F systems was presented using the coupled-cluster singles and doubles excitation approach with perturbation treatment of triple excitations. Mixed basis sets were applied, aug-cc-pCVQZ for the lithium and sodium atoms and aug-cc-pCVDZ for the fluoride atom, with midbond functions (3s3p2d). In total, about 2080 points were generated for three-dimensional surfaces. Both the Li2F and Na2F molecules were confirmed to be bent at equilibrium. For Li-F-Li with an angle of 90°, the depth of the potential well is 3.87 eV at R=2a0, and the height of the barrier required to linearity with 0° angle equals 285.76 eV at R=5.6a0. For Na-F-Na with an angle of 90°, the depth of the potential well is 5.289 eV at R=3a0, and the height of the barrier required to linearity with 0° angle equals 721 eV at R=2.6a0. Our ab initio calculations of potential surface and potential energy surface were compared with the experimental results. |
DOI:10.12693/APhysPolA.142.473 topics: Li2F and Na2F systems, potential energy surface, ab initio calculation, CCSD(T) |