Fingerprint region of the formic acid dimer: variational vibrational computations in curvilinear coordinates

Abstract

Curvilinear kinetic energy models are developed for variational nuclear motion computations including the inter- and the low-frequency intra-molecular degrees of freedom of the formic acid dimer. The coupling of the...

Transfer learned potential energy surfaces: accurate anharmonic vibrational dynamics and dissociation energies for the formic acid monomer and dimer

“…The high-quality PES and DMS 42 were recently employed to assess the fingerprint region of FAD using variational vibrational computations and curvilinear kinetic energy operator representation. 62 Experimentally, the dissociation energy of FAD into two FAMs has been determined from spectroscopy and statistical thermodynamics to be D 0 = 59.5(5) kJ mol À1 (B14.22 kcal mol À1 ). 33 For the double proton transfer barrier, the most recent value from microwave spectroscopy (measured tunneling splitting of 331.2 MHz) is 2559 cm À1 (30.6 kJ mol À1 or 7.3 kcal mol À1 ) from analysis of a 3D model.…”

“…The high-quality PES and DMS 42 were recently employed to assess the fingerprint region of FAD using variational vibrational computations and curvilinear kinetic energy operator representation. 62 …”

CH4·F− revisited: full-dimensional ab initio potential energy surface and variational vibrational states

“…The vibrational kinetic energy operator in terms of general vibrational coordinates can be written in various forms [11]. The Podolsky form has been found to be useful [11,53,54,55] in discrete variable representation (DVR) [56] computations,…”

Exact quantum dynamics developments for floppy molecular systems and complexes

“…where orthogonality of the rotation matrix, O O O T O O O = I I I, allowed us to express the rovibrational g kl elements solely in terms of body-fixed quantities, i.e., using the vibrational and rotational t-vectors, Eqs. (10) and (12), respectively. Regarding the translation-vibration and translationrotation blocks, we use the fact that the translational Jacobi matrix elements are coordinate independent (constant), and we fixed the origin of the body-fixed frame at the nuclear center of mass, Eq.…”

“…An efficient implementation and available computing power typically allows us to use this simple, 'direct'(-product) methodology up to 6-10 fully coupled vibrational degrees of freedom. 10,[30][31][32][33]54 To be able to solve the vibrational Schrödinger equation beyond this system size (or for challenging floppy systems up to a higher energy range already with up to ca. 10 degrees of freedom), it is necessary to develop vibrational methodologies which attenuate the rapid increase of the computational cost with the dimensionality.…”