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arXiv 1803.01124physics.chem-phphysics.ao-ph
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用于红外光谱计算的高精度水势能面

High accuracy water potential energy surface for the calculation of infrared spectra

Irina I. Mizus, Aleksandra A. Kyuberis, Nikolai F. Zobov, Vladimir Yu. Makhnev, Oleg L. Polyansky, Jonathan Tennyson

摘要:

水和CO $_2$等小分子的跃迁强度现在可以以如此高的精度计算,以至于它们被用来系统地取代标准数据库中的测量。这些计算使用高精度从头计算偶极矩表面和波函数从光谱确定的势能面。这里,从从头算PES开始产生水分子(\hato)的超高精度势能面(PES),然后将其细化到经验振转能级。使用该PES的变分核运动计算再现了拟合能级,标准偏差为0.011 \cm,约为其所述不确定度的三倍。使用这种精细PES计算的波函数被发现,以提高选定的(有问题的)过渡的预测过渡强度。提出了一个新的H2(16)O室温谱线表。据建议,相关联的一套线强度是最准确的本物种的日期。

英文摘要:

Transition intensities for small molecules such as water and CO$_2$ can now be computed with such high accuracy that they are being used to systematically replace measurements in standard databases. These calculations use high accuracy ab initio dipole moment surfaces and wavefunctions from spectroscopically-determined potential energy surfaces. Here an extra high accuracy potential energy surface (PES) of the water molecule (\hato) is produced starting from an ab initio PES which is then refined to empirical rovibrational energy levels. Variational nuclear motion calculations using this PES reproduce the fitted energy levels with a standard deviation of 0.011 \cm, approximately three times their stated uncertainty. Use of wavefunctions computed with this refined PES is found to improve the predicted transition intensities for selected (problematic) transitions. A new room temperature line list for H2(16)O is presented. It is suggested that the associated set of line intensities is the most accurate available to date for this species.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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