Hidden aspects of the Structural Theory of chemistry: The MC-QTAIM analysis reveals "alchemical" transformation from a triatomic to a diatomic structure

Abstract

The Structural theory of chemistry introduces chemical/molecular structure as a combination of relative arrangement and bonding patterns of atoms in molecule. Nowadays, the structure of atoms in molecules is derived from the topological analysis of the quantum theory of atoms in molecules (QTAIM). In this context a molecular structure is varied by large geometrical variations and concomitant reorganization of electronic structure that are usually taking place in chemical reactions or under extreme hydrostatic pressure. In this report a new mode of structural variation is introduced within the context of the newly proposed multi-component QTAIM (MC-QTAIM) that originates from mass variation of nuclei. Accordingly, XCN and CNX series of species are introduced where X stands for a quantum particle with a unit of positive charge and a variable mass that is varied in discrete steps between the masses of proton and positron. Ab initio non-Born-Oppenheimer (non-BO) calculations are done on both series of species and the resulting non-BO wavefunctions are used for the MC-QTAIM analysis revealing a triatomic structure for the proton mass and a diatomic structure for the positron mass. In both series of species a critical mass between that of proton and positron mass is discovered where the transition from triatomic to diatomic structure takes place. This abrupt structural transformation has a topological nature resembling the usual phase transitions in thermodynamics. The discovered mass induced structural transformation is a hidden aspect of the Structural theory which is revealed only beyond the BO paradigm when nuclei are treated as quantum waves instead of clamped point charges.

arXiv comment24 pages, 3 figures

References in corpus (4)

• Signature of the existence of the positronium molecule
• Deciphering the "chemical" nature of the exotic isotopes of Hydrogen by the MC-QTAIM analysis: The positively charged Muon and the Muonic Helium as new members of the Periodic Table
• The Two-Component Quantum Theory of Atoms in Molecules (TC-QTAIM): The unified theory of localization/delocalization of electrons, nuclei and exotic elementary particles
• Topological and AIM analyses beyond the Born-Oppenheimer paradigm: New opportunities

Cited by in corpus (14)

• Where to place the positive muon in the Periodic Table?
• Revisiting the foundations of the quantum theory of atoms in molecules: Some open problems
• On the nature of the positronic bond
• Two-component density functional theory for muonic molecules: Inclusion of the electron-positive muon correlation functional
• Incorporating nuclear vibrational energies into the -atom in molecules- analysis: An analytical study
• Developing effective electronic-only coupled-cluster and Muller-Plesset perturbation theories for the muonic molecules
• Toward a muon-specific electronic structure theory: Effective electronic Hartree-Fock equations for the muonic molecules
• The MC-QTAIM: A framework for extending the atoms in molecules analysis beyond purely electronic systems
• Some implications of the Hartree product treatment of the quantum nuclei in the ab initio Nuclear-electronic orbital methodology
• Effective electronic-only Kohn-Sham equations for the muonic molecules
• On the nature of the two-positron bond: Evidence for a novel bond type
• The MC-QTAIM analysis reveals an exotic bond in the coherently quantum superposed Malonaldehyde
• The conceptual and mathematical foundations of the MC-QTAIM
• Extending the topological analysis and seeking the real-space subsystems in non-Coulombic systems with homogeneous potential energy functions