Density functional theory calculations of nuclear quadrupole coupling constants with calibrated 17O quadrupole moments

1999 ◽  
Vol 97 (3) ◽  
pp. 347-354
Author(s):  
G. DE LUCA, N. RUSSO, A. M. KOSTER, P.
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Coupling Constants ◽  
Quadrupole Moments ◽  
Functional Theory ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole

Non-Covalent Functionalisation of C30 Fullerene by Pyrrole-n-Carboxylic Acid (n=2, 3): Density Functional Theory Studies

2017 ◽  
Vol 73 (1) ◽  
pp. 51-56
Author(s):  
Kun Harismah ◽  
Mahmoud Mirzaei ◽  
Nahid Ghasemi ◽  
Mohammad Nejati
Keyword(s):  
Density Functional Theory ◽  
Carboxylic Acid ◽  
Density Functional ◽  
Spherical Shape ◽  
Density Functional Theory Calculations ◽  
Coupling Constants ◽  
Atomic Scale ◽  
Functional Theory ◽  
Quadrupole Coupling ◽  
Non Covalent Interactions

AbstractFor functionalisation of a representative C30 fullerene nanostructure by pyrrole-n-carboxylic acid (PnCA; n=2, 3) their stabilities and properties were investigated based on density functional theory calculations. Parallel calculations were also done for C60 fullerene as evidence for comparing the results. Non-covalent interactions are considered to make the functionalised structures. In contrast with the spherical shape of C60, the shape of C30 fullerene is elliptical; therefore, the functionalisation processes were done for both axial and equatorial elliptical positions (AC30 and EC30). The results indicated that both the positions of C30 have almost equivalent chances to be functionalised by PnCA; but functionalisation by P2CA is slightly more favourable than P3CA, either for C60. The illustrated molecular orbitals’ distributions indicated that the direction of charge transfer could be considered from PnCA counterparts to fullerene counterparts. The molecular properties indicated more reactivity for C30 than for C60 fullerene. Finally, the atomic scale quadrupole coupling constants indicated different roles for N and O atoms of PnCA in the functionalised models.

Density Functional Theory Studies of Bonding in Complexes H3N···XY of Ammonia and Dihalogen Molecules: A Comparison with Experimental Results from Rotational Spectroscopy

2002 ◽  
Vol 57 (6-7) ◽  
pp. 537-543 ◽  
Author(s):  
O. Kh. Poleshchuk ◽  
A. C. Legona
Keyword(s):  
Density Functional ◽  
Natural Bond Orbital ◽  
Coupling Constants ◽  
Rotational Spectroscopy ◽  
Charge Redistribution ◽  
Functional Theory ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole ◽  
Experimental Values

The electron density and nuclear quadrupole coupling constants (NQCC) of the H3N...XY (n a type in Mulliken notation) complexes, (X, Y = F, Cl, Br and I), are analyzed with the aid of density functional calculations. To demonstrate the quality of the calculations, various bond lengths and NQCCs obtained by using the hybrid Becke-Lee-Perdew-Yang functional are compared with the corresponding experimental values determined from rotational spectroscopy. An analysis of the NQCC values and various quantities derived fromthe natural bond orbital approach reveals that the molecular interaction is mainly electrostatic, with probably only a small extent of intermolecular electric charge redistribution on complex formation

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