Benchmark thermochemistry of the hydroperoxyl radical

被引:42
作者
Flowers, BA
Szalay, PG
Stanton, JF [1 ]
Kállay, M
Gauss, J
Császár, AG
机构
[1] Univ Texas, Dept Chem & Biochem, Inst Theoret Chem, Austin, TX 78712 USA
[2] Johannes Gutenberg Univ Mainz, Inst Phys Chem, D-55099 Mainz, Germany
[3] Eotvos Lorand Univ, Dept Theoret Chem, H-1518 Budapest 112, Hungary
关键词
D O I
10.1021/jp037347j
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
A theoretical estimation of the enthalpy of formation for the hydroperoxyl radical is presented. These results are based on CCSD(T)/aug-cc-pCV5Z calculations extrapolated to the basis-set limit with additional corrections. Anharmonic vibrational zero-point energies, scalar relativistic, spin-orbit coupling, and diagonal Born-Oppenheimer corrections are further used to correct the extrapolated term energies, as well as various empirical corrections that account for correlation effects not treated at the CCSD(T) level. We estimate that Delta(f)H(0)degrees = 3.66 +/- 0.10 kcal mol(-1) (Delta(f)H(298)degrees = 2.96 +/- 0.10 kcal mol(-1)) using several reaction schemes. Significantly, it appears to be necessary to include effects of connected pentuple excitations in order to achieve an uncertainty of ca. 0.1 kcal mol(-1).
引用
收藏
页码:3195 / 3199
页数:5
相关论文
共 40 条