The importance of an accurate target wavefunction in variational calculations for (e+–H2) scattering
The importance of an accurate target wavefunction in variational calculations for (e+–H2) scattering
复制标题
准确的目标波函数在 (e+–H2) 散射变分计算中的重要性
DOI：
--
复制
发表时间：
2008
期刊：
影响因子：
--
通讯作者：
M. Plummer
中科院分区：
文献类型：
--
作者：
J. N. Cooper;E. Armour;M. Plummer
用复Kohn方法计算了正电子被分子氢弹性散射的相移和湮没参数ZJeff的变分值。我们的结果对表示目标氢分子的波函数的精度的微小变化很敏感。我们已经发展了一种系统的方法来证明，在低正电子能量下，有一些特殊形式的Kohn试探波函数的变分计算结果是不可靠的，即使当目标波函数占H2关联能量的96.8%时也是如此。我们发现，如果我们的计算扩展到包含更复杂的目标波函数，占关联能量的99.7%，则可以恢复可靠的结果。简要讨论了理论和实验之间的剩余差异。
Using the complex Kohn method, we have calculated variational values of phase shifts and the annihilation parameter, Zeff, for the elastic scattering of positrons by molecular hydrogen. Our results are sensitive to small changes in the accuracy of the wavefunction representing the target hydrogen molecule. We have developed a systematic approach to demonstrate that, at low positron energies, there are particular forms of the Kohn trial wavefunction for which the results of variational calculations are not reliable, even when the target wavefunction accounts for as much as 96.8% of the correlation energy of H2. We find that reliable results can be recovered if our calculations are extended to admit more sophisticated target wavefunctions accounting for 99.7% of the correlation energy. Remaining discrepancies between theory and experiment are briefly discussed.