A time-dependent Hartree-Fock approach for studying the electronic optical response of molecules in intense fields
A time-dependent Hartree-Fock approach for studying the electronic optical response of molecules in intense fields
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DOI：
10.1039/b415849k
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发表时间：
2005-01-01
影响因子：
3.3
通讯作者：
Schlegel, HB
中科院分区：
文献类型：
--
作者：
Li, XS;Smith, SM;Schlegel, HB
对于处于高强度振荡电场中的分子，用含时Hartree-Fock（TDHF）方法模拟电离前的电子密度行为。由于微扰方法在这些强度下不再有效，因此使用完整的TDHF方程来传播电子密度。一个酉变换的方法相结合的修改中点法，提供了一个稳定和有效的算法来整合这些方程。用STO-3G基组的TDHF方法计算了H-2（+）在强振荡场中的行为，再现了两态相干激发模型的解析解。对于H-2和6-311++G（d，p）基组，TDHF结果几乎与使用全含时薛定谔方程的计算没有区别。在3.17 × 10（13）W cm（-2）和456 nm的振荡场中，H-2的分子轨道能量、电子布居和原子电荷随场的变化而变化。随着场强的增加，响应变得更加复杂，作为激发态的贡献的结果。N-2的模拟显示出更大的复杂性，但平均电荷仍然以几何学的方式跟随场。
For molecules in high intensity oscillating electric fields, the time-dependent Hartree-Fock (TDHF) method is used to simulate the behavior of the electronic density prior to ionization. Since a perturbative approach is no longer valid at these intensities, the full TDHF equations are used to propagate the electronic density. A unitary transform approach is combined with the modified midpoint method to provide a stable and efficient algorithm to integrate these equations. The behavior of H-2(+) in an intense oscillating field computed using the TDHF method with a STO-3G basis set reproduces the analytic solution for the two-state coherent excitation model. For H-2 with a 6-311++G(d,p) basis set, the TDHF results are nearly indistinguishable from calculations using the full time-dependent Schrodinger equation. In an oscillating field of 3.17 x 10(13) W cm(-2) and 456 nm, the molecular orbital energies, electron populations, and atomic charges of H-2 follow the field adiabatically. As the field intensity is increased, the response becomes more complicated as a result of contributions from excited states. Simulations of N-2 show even greater complexity, yet the average charge still follows the field adiabatically.