MCSCF-CI Calculations of Radiative Transition Probabilities of PH and PD

Senekowitsch, Jörg; Rosmus, P.; Werner, Hans‐Joachim; Larsson, Mats

doi:10.1515/zna-1986-0504

Cited by 22 publications

(4 citation statements)

References 11 publications

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“…The reaction barrier on the 3 A 0 surface appears to lie at a collinear geometry [39]. Based on the barrier heights on the 3 A 00 surfaces at collinear geometries, we conclude that this barrier is about 2 kcal/mol or more higher than the bent saddle points on the four surfaces considered here.…”

Section: Resultsmentioning

confidence: 54%

Variational transition state theory calculations of thermal rate coefficients for the O(3P)+HCl reaction

Allison¹,

Ramachandran²,

Senekowitsch³

et al. 1998

Journal of Molecular Structure: THEOCHEM

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Variational Transition State Theory (VTST) calculations of the thermal rate coefficients of the reaction of O( 3 P ) with HCl are presented. Four potential surfaces for the 3 A 00 state are studied, three of them due to Ramachandran, Senekowitsch, and Wyatt (RSW), based on fits to scaled MR-CISD+Q energies and the fourth one due to Koizumi, Schatz, and Gordon (KSG), based on scaled MP2/6-31G(d,p) energies. Using the program polyrate, version 7.3, the rate coefficients are calculated using Improved Canonical Variational Theory (ICVT) with the microcanonical Optimized Multidimensional Tunneling (¹OMT) approximation over the temperature range 200¡1500 K. These results are compared to available experimental data, which lie in the range 293¡1486 K. It is found that the RSW surfaces yield thermal rate coefficients that are in reasonable agreement with experimental data over this range, and in very good agreement for T > 500 K, while those computed on the KSG surface are somewhat higher. These comparisons indicate that one of the RSW surfaces may establish an upper limit for the correct reaction barrier for this reaction while the KSG surface could provide a lower limit.

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Section: Resultsmentioning

confidence: 54%

Variational transition state theory calculations of thermal rate coefficients for the O(3P)+HCl reaction

Allison¹,

Ramachandran²,

Senekowitsch³

et al. 1998

Journal of Molecular Structure: THEOCHEM

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“…The results obtained with these various methods for the dipole moment of CH (refs. 58-60), NH (58,(61)(62)(63)(64), OH (58,(65)(66)(67)(68), SiH (58,(69)(70)(71)(72), PH (58,72,73), and SH (58,72,74) in their ground electronic states are summarized in Table 7 together with our UGA-CCSD(is) results. A1 the results for CH are within the experimental error bounds, the CCSD(is) value being the smallest of them all.…”

Section: Resultsmentioning

confidence: 99%

Calculation of static molecular properties in the framework of the unitary group based coupled cluster approach

Paldus¹,

Li²

1996

Can. J. Chem.

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The recently developed and implemented state selective, fully spin-adapted coupled cluster (CC) method that employs a single, yet effectively multiconfigurational, spin-free reference and the formalism of the unitary group approach (UGA) to the many-electron correlation problem, has been employed to calculate static electric properties of various open-shell ( 0 s ) systems using the finite field (FF) technique. Starting with the lithium atom, the method was applied at the first-order interacting space single and double excitation level (CCSD(is)) to several first-and second-row hydrides having OS ground state, namely to the CH, NH, OH, SiH, PH, and SH radicals. In the case of NH we also considered three OS excited states. In all cases the dipole moment and polarizability were determined using a high quality basis set and compared with the experiment, whenever available, as well as with various configuration interaction results and other theoretical results that are available from the literature. The agreement of our CCSD(is) values with experiment is very satisfactory except for the 3~-ground state of the NH radical, where the experimentally determined dipole moment is too small. No experimental data are available for the corresponding polarizabilities. It is also shown that the FF technique is not suitable for calculations of higher order static properties, such as the hyperpolarizability P and y tensors. For this reason we formulate the linear response version of our UGA-based CCSD approach and discuss the aspects of its future implementation.Key words: static molecular properties, dipole moments, polarizabilities, free radicals, unitary group based coupled cluster method, linear response theory, finite field technique.RCsurnC : On a utilisk la mtthode des cccoupled cluster,, (((CCn) complktement adaptCe aux spin et sClective des Ctats, dCveloppCe et mise en place rkcemment, qui n'utilise qu'une rCfCrence sans spin, mais qui est malgrC tout effectivement multiconfigurationnelle, ainsi que le formalisme de groups unitaires (NUGAD) au problkme de la corrClation de plusieurs Clectrons pour calculer les propriCtCs statiques de divers systernes en couches ouvertes (c

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“…An AV5Z basis set at the coupled cluster (CCSD(T)) level of theory produced a dipole moment of 0.4410 D. Other studies at the configuration-interaction (CI) level calculated the dipole moment as 0.431 D (Senekowitsch et al 1986) and 0.432 D (Park & Sun 1992).…”

Section: Potential Energy Curvementioning

confidence: 99%

ExoMol line list – XXXIV. A rovibrational line list for phosphinidene (PH) in its $X\, {}^3\Sigma ^-$ and $a\, {}^1\Delta$ electronic states

Langleben

Tennyson

Yurchenko

et al. 2019

Monthly Notices of the Royal Astronomical Society

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A rovibronic line list for the ground (X 3 Σ − ) and first excited (a 1 ∆) states of phosphinidene, 31 PH, is computed. The line list is designed for studies of exoplanetary and cool stellar atmospheres with temperatures up to 4000 K. A combination of empirical and ab initio data are used to produce the line list: potential energy curves (PECs) are fitted using experimental transition frequencies; these transitions are reproduced with a root mean square error of 0.01 cm −1 . The nuclear Schrödinger is solved using these PECs plus Born-Oppenheimer and spin splitting correction terms. Line intensities and Einstein A coefficients are computed using ab initio Dipole Moment Curves (DMC) X-X and a-a. The resulting LaTY line list, which contains 65055 transitions for 2528 rovibronic states up to 24500 cm −1 and J = 80, is used to simulate spectra in emission and absorption at a range of temperatures. The line list is made available in electronic form at the CDS and ExoMol databases.

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MCSCF-CI Calculations of Radiative Transition Probabilities of PH and PD

Cited by 22 publications

References 11 publications

Variational transition state theory calculations of thermal rate coefficients for the O(3P)+HCl reaction

Variational transition state theory calculations of thermal rate coefficients for the O(3P)+HCl reaction

Calculation of static molecular properties in the framework of the unitary group based coupled cluster approach

ExoMol line list – XXXIV. A rovibrational line list for phosphinidene (PH) in its $X\, {}^3\Sigma ^-$ and $a\, {}^1\Delta$ electronic states

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