Trabelsi T, Mahjoubi K, Mehnen B, Hochlaf M, Francisco J S
Department of Earth and Environment Science and Department of Chemistry , University of Pennsylvania , Philadelphia , Pennsylvania 19104-6243 , United States.
Laboratoire Modélisation et Simulation Multi Echelle , Université Paris-Est, MSME UMR 8208 CNRS , 5 bd Descartes , 77454 Marne-la-Vallée , France.
J Phys Chem A. 2019 Jan 17;123(2):463-470. doi: 10.1021/acs.jpca.8b07843. Epub 2019 Jan 7.
Standard and explicitly correlated coupled-cluster theory computations in conjunction with large basis sets are performed to characterize [Al,P,O] isomers. Three isomers, namely, linear-AlOP, bent-AlOP, and linear-OAlP, are found to be stable species. Their optimized equilibrium geometries, harmonic vibrational frequencies, rotational constants, and relative energies are deduced. In addition, a set of spectroscopic parameters is generated from the three-dimensional potential energy surfaces of each isomer at the (R)CCSD(T)/aug-cc-pV5Z level. The linear isomers have an XΣ electronic ground state and are characterized as weakly bound systems or floppy molecules due to their low-frequency bending modes (<150 cm). The dipole moment of linear-AlOP is calculated to be 1.48 D. By comparison, a much larger dipole moment is computed for linear-OAlP (5.01 D), indicating lower ionic character in AlOP. Both the linear-OAlP and linear-AlOP isomers are suggested to be good candidates for detection in interstellar media by radio astronomy.
采用标准且明确相关的耦合簇理论计算方法，并结合大基组来表征[Al, P, O]异构体。发现三种异构体，即线性-AlOP、弯曲-AlOP和线性-OAlP，是稳定的物种。推导了它们优化后的平衡几何结构、谐振动频率、转动常数和相对能量。此外，在(R)CCSD(T)/aug-cc-pV5Z水平下，从每个异构体的三维势能面生成了一组光谱参数。线性异构体具有XΣ电子基态，由于其低频弯曲模式（<150 cm），被表征为弱束缚系统或松散分子。计算得出线性-AlOP的偶极矩为1.48 D。相比之下，线性-OAlP的偶极矩要大得多（5.01 D），这表明AlOP中的离子特性较低。线性-OAlP和线性-AlOP异构体都被认为是射电天文学在星际介质中进行探测的良好候选对象。
