Twofold diabatization of the KRb(1–2)Π1complex in the framework ofab initioand deperturbation approaches

Abstract

The twofold diabatization of the KRb (1 ∼ 2) We performed a diabatization of the mutually perturbed 1 1 Π and 2 1 Π states of KRb based on both electronic structure calculation and direct coupled-channel deperturbation analysis of experimental energies. The potential energy curves (PECs) of the diabatic states and their scalar coupling were constructed from the ab initio adiabatic PECs by analytically integrating the radial ψ ad 1 |∂/∂R|ψ ad 2 matrix element obtained by a finite-difference method. The diabatic potentials and electronic coupling function were refined by the least squares fitting of the rovibronic termvalues of the 1 1 Π ∼ 2 1 Π complex. The empirical PECs combined with the coupling function as well as the diabatized spin-orbit coupling and transition dipole matrix elements are useful for further deperturbation treatment of both singlet and triplet states manifold. I. INTRODUCTIONThe accurate representation of the interacting electronic states plays a key role in understanding the detailed mechanism of the photo and collisionally induced chemical reactions. The singlet-triplet levels of alkali metal dimers serve as an intermediate state in the two step optical transformation of the weakly bound atomic pairs into the absolute ground X 1 Σ + (v = 0, J = 0) molecular state 1,2 . To suppress the undesired spontaneous transitions to the low-lying states a coherent stimulated Raman adiabatic passage 3 (STIRAP) is often used.The photoassociative production and trapping of ultracold KRb molecules has been performed 4 . The resonance coupling of the B(1) 1 Π and 2 1 Π states of KRb (see, Fig. 1) is found to be a promising pathway for direct photoassociative formation of the X(0, 0) ultracold molecules 5 . The rigorous multi-channel modeling of the laser formation of vibrationally cold KRb molecules has been accomplished in Ref. 6 9,10 to the lowest X(0, 0) level through the B 1 Π ∼ c 3 Σ + levels located near the second dissociation threshold.A comprehensive review of modern spectroscopic studies of the KRb electronic states can be found in the ebook 12 . The mutually perturbed 1 1 Π and 2 1 Π states converging to the second K(4 2 S)+Rb(5 2 P) and third K(4 2 P)+Rb(5 2 S) dissociation thresholds were investigated 13,14 using Doppler-free optical-optical double resonance polarization spectroscopy (OODRPS). In the sub- 15,16 included in the present CC deperturbation analysis. The inset enlarges the region in the vicinity of the crossing point of V1(R) and V2(R) diabatic PECs.The adiabatic potentials, permanent and transition dipole moments for the radially coupled 1 1 Π and 2 1 Π states were first ab initio calculated in Refs 19 and 20. The comprehensive set of non-relativistic PECs, permanent and transition dipole moments for the ground and excited states of KRb are available 11,21-25 as well. The SOC effect has been included into ab initio calculations in Refs. 6,11,24,and 26. Among other alkali diatomics, the KRb molecule stands out because of the high density of the electronic states belonging to both...

Rydberg states of OH radical

“…When going from BOA to IBOA, a radical rearrangement of the RE spectrum occurs, in particular, its dependence on the dipole moment of the core. We emphasize that IBOA in our case is associated with the slow motion corresponding to electronic degrees of freedom compared to rotational, but not vibrational one, as it is usually understood for low-excited states of molecules [41][42][43].…”

Редуцированный метод связанных колебательных каналов: анализ регулярных возмущений в c^3 Sigma-=SUB=-Omega-=/SUB=--=SUP=-+-=/SUP=--состоянии молекулы KRb

“…Для учета динамической электронной корреляции использовали метод конфигурационного взаимодействия с предварительной оптимизацией молекулярных орбиталей методом многоконфигурационного самосогласованного поля в полном активном пространстве. Более подробное описание методики может быть найдено в работах [5,9].…”

“…Функции потенциальной энергии для электронных состояний b 3 , B 1 , D 1 и d 3 являлись фиксированными в данной модели. Они были получены ранее в результате неадиабатического анализа [5,9], выполненного в тех областях энергий возбуждения, где взаимодействиями с c 3 + -состоянием можно пренебречь. Следует отметить, что для матричных элементов спинорбитального взаимодействия с B-и D 1 -состояниями было использовано диабатическое представление [9], которое позволяет наиболее адекватно описать неадиабатические взаимодействия состояний одной симметрии.…”

Ридберговские Состояния Радикала ОН

“…При переходе от BOA к IBOA происходит радикальная перестройка спектра RE, в частности, его зависимость от дипольного момента остова. Подчеркнем, что IBOA в нашем случае связано с медленностью движения, соответствующего электронным степеням свободы, по сравнению с вращательными, а не с колебательными, как это обычно понимается для низковозбужденных состояний молекул [41][42][43].…”