烟道气体SO_2同位素分子配分函数模拟计算  

Partition Functions of Molecule SO_2

作　　者：伍冬兰[1] 谢安东[1] 万慧军[1] 

机构地区：[1]井冈山大学数理学院,江西吉安343009

出　　处：《计算物理》2011年第5期755-760,共6页Chinese Journal of Computational Physics

基　　金：国家自然科学基金(10965002);江西省教育厅科学技术项目(2007326);江西省自然科学基金(2010GQW0031)资助项目

摘　　要：利用Gaussian03程序包,在B3P86/cc-PV5Z水平上对烟道气体SO2同位素分子进行优化计算,得到平衡几何结构、谐振频率和转动常数等物理性质参数;采用乘积近似法构建两种分子的配分函数模型,其中,转动配分函数采用WATSON的刚性转子模型,振动配分函数采用谐振子近似.模拟计算两种分子70～6 000 K温度范围内的总配分函数,并将70～3 000 K的数据与数据库比较,发现两者符合的较好,且随着温度升高,相对偏差逐渐增大,但差值都小于4%;相对偏差与温度可以近似看成一条直线,通过对相对偏差进行线性拟合,进而修正高温区(3 000～6 000 K)的计算,用一个温度T的多项表达式对高温区修正了的配分函数进行拟合,获得五个拟合系数,可以快速地获得高温区任意温度的配分函数,从而给出在高温下较为准确的分子配分函数.Geometrical structures of32 S16 02 and34 S16 02 are optimized at B3P86/cc-PV5Z level using Gaussian03 program. Equilibrium geometry, vibrational and rotational constants etc. are obtained. Total internal partition functions （TIPF） of32S1602 and34 STM O2 are calculated from 70 to 6000K with product approximation. Rotational partition sums adopt WATSON rigidrotator model and vibrational partition sums use harmonic oscillator approximation. It is found that calculated results are consistent with those offered by HITRAN database, and errors show linear correlation approximately from 70 to 3000 K. By fitting errors, TIPF were corrected at high temperatures range from 3000 to 6000 K. Corrected values are fitted to a four-order polynomial of T, and coefficients are evaluated. This allows a rapid and accurate calculation of TIPF at 3 000 - 6 000 K.

关 键 词：烟道气体 SO2 同位素 配分函数 

分 类 号：O561[理学—原子与分子物理]