Absorption intensities of zero-phonon single and double transitions in the multipole-induced spectrum of solid hydrogen

Orientationalortho−H2pair interactions in the microporous framework MOF-5

“…In the case of solid hydrogen, interacting H 2 pairs lead to so called double transitions 29,30 . These are ones in which two molecules are excited by a single photon and arise through the quadrupole field of one H 2 inducing a dipole moment via the polarizability of a second H 2 3,5,6 .…”

Effect of orthohydrogen impurity on the absorption intensities of single transitions in a solid parahydrogen crystal

“…(1) and (2) are to be multiplied by the appropriate phonon renormalization factors n 2 s or n d , which correct the rigid lattice sums for the zero-point motions [13][14][15][16][17][18][19][20]. The phonon renormalization factors are not easily amenable for calculations, a priori and it is customary to set them equal to unity.…”

“…In solid hydrogen, since the transitions originate due to multipolar induction, the internal energy of a single molecule (single transition) or a pair of molecules (double transitions) is changed upon absorption of a single photon. The expressions for the intensity of single and double transitions involve sums over the entire lattice [13][14][15][16][17][18][19][20]. In case of single transitions, the lattice sums are affected by the cancellation effect due to crystal-symmetry.…”

“…Study of absorption intensity of multipole field-induced transitions in solid hydrogen has provided, over the years, a fundamental testing ground for both theory and experiment [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. In solid hydrogen, since the transitions originate due to multipolar induction, the internal energy of a single molecule (single transition) or a pair of molecules (double transitions) is changed upon absorption of a single photon.…”

Rovibrational matrix elements of the multipole moments and of the polarizability of the H2 molecule in the solid phase: Effect of intermolecular potential

“…Its multipole moments´Q µ and linear polarizability have been the subject of many theoretical investigations [1][2][3][4][5][6][7][8][9][10]. The matrix elements given in the previous works, strictly speaking, have been calculated for the free molecules, but invariably, these gas phase results have been used in the elucidation of absorption features in the characteristic infrared spectrum displayed by H 2 in the condensed state [9][10][11][12][13][14][15]. The justification for the adoption of the matrix elements of the free hydrogen molecule to the solid phase will have to rest on rigorous calculations which have not been attempted before.…”