Theoretical structure of crystalline benzene

Dzyabchenko, A. V.; Bazilevskii, M. V.

doi:10.1007/bf00754129

Cited by 5 publications

(3 citation statements)

References 8 publications

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“…Thi6ry & R6rat (1996) used a complex force field in an endeavour to identify the high-pressure phase benzene (II). They concluded that a P21/c structure, which had also been found by several other workers (Dzyabchenko & Bazilevskii, 1985a;Tajima et al, 1995;Gibson & Scheraga, 1995), is the most stable in the pressure range 5-10 kbar. However, agreement between the calculated and observed powder diffraction diagram was poor.…”

Section: Introductionsupporting

confidence: 67%

“…Starting from 200 initial models with reasonable intermolecular distances, selected to sample the entire range of possible parameters for special settings in four space groups, he arrived at 17 possible crystal structures. At pressures over 2.2 kbar, benzene (III) was calculated to be more stable than benzene (I) (Dzyabchenko & Bazilevskii, 1985a). In a subsequent study Dzyabchenko (1987) allowed two independent molecules in special positions in space group e21/C (Z = 4).…”

Section: Introductionmentioning

confidence: 97%

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Hypothetical Crystal Structures of Benzene at 0 and 30 kbar

Eijck¹,

Spek²,

Mooij³

et al. 1998

Acta Crystallogr Sect B

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Possible crystal structures of benzene were generated without any prior crystallographic information, using a systematic grid search method. Only structures with one molecule in the asymmetric unit were considered. 31 space groups were investigated, and the resulting structures were clustered and checked for stability upon removal of the space-group symmetry. In the enthalpy range "~10 kJ mo1-1 30 structures were found at zero pressure and 20 structures at a pressure of 30 kbar. Their pressure-dependent rankings and interconversions are discussed. The results are compared to previous, less complete, investigations. A possible structure for the high-pressure phase benzene (II), on which only limited powder diffraction data have been published, is suggested.

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Section: Introductionsupporting

confidence: 67%

Section: Introductionmentioning

confidence: 97%

Hypothetical Crystal Structures of Benzene at 0 and 30 kbar

Eijck¹,

Spek²,

Mooij³

et al. 1998

Acta Crystallogr Sect B

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“…The availability of high-pressure experimental data on the biphenyl phases (Cailleau, 1986;Cailleau et al, 1986;Moussa et al, 1987) provides an extra opportunity to verify our model. To take the hydrostatic pressure into account, the enthalpy H = E + PV was minimized (Dzyabchenko & Bazilevskii, 1985). Here E is the lattice energy, and V is the unit-cell volume per molecule.…”

Section: Effect Of Pressure On the Biphenyl Structurementioning

confidence: 99%

Model for the crystal packing and conformational changes of biphenyl in incommensurate phase transitions

Dzyabchenko

Scheraga

2004

Acta Crystallogr Sect B

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Standard atom-atom potentials for hydrocarbons and a torsional potential to account for the pi-electron conjugation energy were used to model the crystal structures and phase transitions of biphenyl. The model describes the high-temperature phase (I) with its planar molecule as a stationary point of the energy hypersurface. Phase I represents a low-energy barrier between the symmetry minima of the ground state (phase III), in which the molecule is twisted with torsion angles of opposite sign. Global-energy minimization was carried out by considering both regular structures, with one or two independent molecules, and quasi-one-dimensional superstructures built of N cells (N up to 16) of the high-temperature structure. The various energy-minimized biphenyl structures demonstrate remarkable similarity in their crystal packing; in particular, there are characteristic rows of cooperatively twisted molecules parallel to the superstructure dimension b. The structures built of centrosymmetric rows (P1, Z = 4 and 8) are almost as low in energy as the basic structure (an N = 2 superstructure, Pa, Z = 4); moreover, one of them is isostructural with the low-temperature p-quaterphenyl structure. With N > 8, structures of lower energy than that of the basic structure (N = 2) were found; their common feature is an M-fold modulation of the twist angle over the supercell period, with M smaller than N and generally not a simple fraction of it. The global minimum was found to conform to the ratio k = M/N = 6/14, which is close to the experimentally observed k = 6/13 in the incommensurate phase III. Enthalpy minimization showed an overall decrease in the magnitude of the twist angle down to tau approximately 0 degrees, as well as the evolution of the modulated structures towards the high-temperature structure with increasing pressure, in agreement with evidence for the high-pressure limit of the incommensurate biphenyl phases.

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Force field development phase II: Relaxation of physics-based criteria… or inclusion of more rigorous physics into the representation of molecular energetics

Hagler

2018

J Comput Aided Mol Des

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Theoretical structure of crystalline benzene

Cited by 5 publications

References 8 publications

Hypothetical Crystal Structures of Benzene at 0 and 30 kbar

Hypothetical Crystal Structures of Benzene at 0 and 30 kbar

Model for the crystal packing and conformational changes of biphenyl in incommensurate phase transitions

Force field development phase II: Relaxation of physics-based criteria… or inclusion of more rigorous physics into the representation of molecular energetics

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