scispace - formally typeset
Search or ask a question
Journal ArticleDOI

Topological effects in low-lying electronic states of linear N2H2 + and HBNH+ associated with onset of bending

13 Apr 2018-Molecular Physics (Informa UK Limited)-Vol. 116, pp 2642-2651
TL;DR: In this paper, the authors investigated the topological effects of Renner-Teller conical interactions in slightly bent N2H2+ and HBNH+ and found that the appearance of JT-CIs is in molecular plane while for N 2H2+, in certain nonplanar configuration, in sharp contrast to th...
Abstract: The current decade has seen illuminating and extensive study of interplay of topological effects such as Renner–Teller and Jahn–Teller (JT) effects in small molecules. Study of such effects in HCNH molecule showed an interesting feature that for slightly bent system, a pair of JT conical interactions (CIs) appear only for certain nonplanar configuration, in contrast to its appearance in CS configuration (molecular plane) for C2H2+. Moreover, since the feature of appearance of JT-CIs in two 2Σ+ states of HCNH in some bent configuration may be critically associated to the abundance of HNC in interstellar spaces, as advocated recently by Das and Mukhopadhyay (J. Phys. Chem. 117, 8680 (2013)), the interest in such topological studies have remained relevant. In this article we have investigated such topological effects for slightly bent N2H2+ and HBNH+. Interestingly, the appearance of JT-CIs are, for HBNH+, in molecular plane while for N2H2+, in certain nonplanar configuration, in sharp contrast to th...
Citations
More filters
Posted Content
TL;DR: In this article, the authors investigate the relationship between JTCI and RTPI in the linear tetra-atomic molecular system with slightly bent HCNOplus, a motivated choice of tetraatomic with all four different atoms.
Abstract: Search for configuration space with welldefined topological (Berry) phases corresponding to Jahn Teller (JT) conical intersection (CI) and Renner Teller(RT) parabolic intersection (PI) in the linear tetra-atomic molecular system on introduction of bending, reveal the interesting aspect that these potential intersections may appear in molecular plane as well as out of the molecular plane. While understanding this aspect is important for following the class of phenomena led by potential intersections, till date studies on molecular systems including pairs like (C2H2plus , HCNH) as well as (N2H2plus , HBNHplus ), have not been able to clarify the issue. The present paper embodies calculation of non-adiabatic coupling terms (NACTs) involving four low lying states of slightly bent HCNOplus , a motivated choice of tetra-atomic with all four different atoms, to study this aspect associated with JTCI and RTPI in slightly bent linear system. The plane of appearance of these effects, has been advocated to be related to electronic configuration of the concerned states of the molecular system.
Journal ArticleDOI
TL;DR: In this paper, the authors investigate the relationship between JTCI and RTPI in the linear tetra-atomic molecular system with slightly bent HCNOplus, a motivated choice of tetraatomic with all four different atoms.
Abstract: Search for configuration space with welldefined topological (Berry) phases corresponding to Jahn Teller (JT) conical intersection (CI) and Renner Teller(RT) parabolic intersection (PI) in the linear tetra-atomic molecular system on introduction of bending, reveal the interesting aspect that these potential intersections may appear in molecular plane as well as out of the molecular plane. While understanding this aspect is important for following the class of phenomena led by potential intersections, till date studies on molecular systems including pairs like (C2H2plus , HCNH) as well as (N2H2plus , HBNHplus ), have not been able to clarify the issue. The present paper embodies calculation of non-adiabatic coupling terms (NACTs) involving four low lying states of slightly bent HCNOplus , a motivated choice of tetra-atomic with all four different atoms, to study this aspect associated with JTCI and RTPI in slightly bent linear system. The plane of appearance of these effects, has been advocated to be related to electronic configuration of the concerned states of the molecular system.
References
More filters
Journal ArticleDOI
TL;DR: A combined study using both the potential intersections and the angular nonadiabatic coupling terms (NACTs) and report two new results: the appearance of the JT conical intersections (ci's) between the two lowest states of a slightly bent HCNH molecule and the existence of the intersection of the state 1(2)A" with the state 2( 2)A'.
Abstract: Demonstration of onset of Jahn–Teller (JT) intersections, characterized by a topological phase of π, on introduction of bending in the collinear tetra-atomic C2H2+ cation, originally a Renner–Teller (RT) system, has raised interest in the study of the generality of this phenomenon. This interest has initiated similar study by shifting one external light atom from the collinear molecular axes of systems such as HCNH and HC2O. Recent studies have revealed that slightly bent HCNH poses a specialty in this regard and thus demands focused attention. In the present work we performed a combined study using both the potential intersections and the angular nonadiabatic coupling terms (NACTs) and report two new results: (i) The first result is the appearance of the JT conical intersections (ci’s) between the two lowest states of a slightly bent HCNH molecule (12A′ and 12A″, originated from collinear X2Π state) only with certain nonplanar configurations, in contrast to its appearance in CS configuration space (molec...

19 citations

Journal ArticleDOI
TL;DR: Generalized Born-Oppenheimer equations including the geometrical phase effect are derived for three- and four-fold electronic manifolds in Jahn-Teller systems near the degeneracy seam and shows unprecedented simplicity while depicting all features of more elaborated ones.
Abstract: Generalized Born–Oppenheimer equations including the geometrical phase effect are derived for three- and four-fold electronic manifolds in Jahn–Teller systems near the degeneracy seam The method is readily extendable to N-fold systems of arbitrary dimension An application is reported for a model threefold system, and the results are compared with Born–Oppenheimer (geometrical phase ignored), extended Born–Oppenheimer, and coupled three-state calculations The theory shows unprecedented simplicity while depicting all features of more elaborated ones

14 citations

Journal ArticleDOI
TL;DR: In this article, the authors performed ab initio calculation using MOLPRO on the 2 2 E and 1 2 A 1 states of Na 3 cluster and explore for locating the point of conical intersections (CIs) in the configuration space (CS).

14 citations

Journal ArticleDOI
TL;DR: This article considers for the first time molecular configurations that avoid any symmetry conditions or, in other words, are characterized by the C(1) point group and reports on a detailed study of topological effects formed by such a molecular system.
Abstract: During the last decade the study of topological effects formed by molecular systems became a routine but it was always carried out for configurations that were limited by symmetry conditions. To be more specific this applied to the Jahn-Teller (JT) effect formed by molecular configurations of planar symmetry [see, e.g., Baer et al., Faraday Discuss. 127, 337 (2004)] and the Renner-Teller effect formed by configurations of axial symmetry [see, e.g., Halasz et al., J. Chem. Phys. 126, 154309 (2007)]. In this article we consider for the first time molecular configurations that avoid any symmetry conditions or, in other words, are characterized by the C1 point group. We report on a detailed study of topological effects formed by such a molecular system. The study concentrates on both, the two-state (Abelian) case and the multistate (non-Abelian) case. It is shown that the theory that was originally developed to treat topological effects due the JT intersection and also applies for the study of topological eff...

13 citations

Journal ArticleDOI
TL;DR: This study reports for the first time that the conical intersection (CI) between the states 1( 2)Σ(+) and 2(2)΢(+) exists only in some bent geometry (and not in the collinear geometry) where both of these states have A' symmetry.
Abstract: Abnormal abundance of HNC in interstellar spaces has been the motivation of many experimental as well as theoretical studies of the branching ratio [HNC]/[HCN] in the dissociation of HCNH, right after its formation from electron capture by HCNH(+), available in the upper atmosphere. In the present work we were interested in nonadiabatic studies involving the dissociation channel of HCNH leading to the formation of HNC. This study reports for the first time that the conical intersection (CI) between the states 1(2)Σ(+) and 2(2)Σ(+) exists only in some bent geometry (and not in the collinear geometry) where both of these states have A' symmetry. This finding is important as this CI is crucial in the dissociation of HCNH. We further report that these two states strongly couple with 1(2)Π, the lowest electronic state of collinear HCNH. Hence we construct a three-state Hilbert subspace (HSS), comprising of the states 1(2)Π, 1(2)Σ(+), and 2(2)Σ(+), in a configuration space where these states interact very strongly and the adiabatic-to-diabatic transformation angles (mixing angle) yield meaningful values of topological (Berry) phase. This leads to the construction of the corresponding three-state diabatic potentials. We advocate that these diabatic potentials, considering both the linear as well as bent configurations, nicely elucidate the formation of the HNC molecule by the CH bond dissociation of HCNH molecule.

11 citations