scholarly journals Modelling temperature-dependent properties of polymorphic organic molecular crystals

2016 ◽  
Vol 18 (45) ◽  
pp. 31132-31143 ◽  
Author(s):  
Jonas Nyman ◽  
Graeme M. Day
Keyword(s):  
Thermal Expansion ◽  
Molecular Crystals ◽  
Temperature Dependent ◽  
Relative Stabilities ◽  
Organic Molecular Crystals ◽  
Temperature Dependent Properties

We examine the importance of thermal expansion on relative stabilities and properties of crystalline polymorphs.

Transient Thermoelastic Problem for an Infinite Medium With a Spherical Cavity Exhibiting Temperature-Dependent Properties

1962 ◽  
Vol 29 (2) ◽  
pp. 399-407 ◽  
Author(s):  
Jerzy Nowinski
Keyword(s):  
Thermal Expansion ◽  
Shear Modulus ◽  
Perturbation Method ◽  
Temperature Rise ◽  
Spherical Cavity ◽  
Infinite Medium ◽  
Thermoelastic Problem ◽  
Linear Variation ◽  
Temperature Dependent ◽  
Temperature Dependent Properties

This paper is concerned with a polarly symmetric transient thermoelastic problem for an infinite medium with a spherical cavity, the boundary of the cavity being subjected to a sudden temperature rise. Thermal and elastic properties of the medium are assumed to be temperature dependent. Using the perturbation method general equations for the displacements and stresses corresponding to particular boundary-value problems have been found. An illustrative example, involving linear variation of conductivity and thermal expansion as well as quadratic variation of shear modulus with temperature, has been discussed in detail.

Elastische und thermoelastische Konstanten des rhombischen α-Schwefels

1969 ◽  
Vol 24 (5) ◽  
pp. 865 ◽  
Author(s):  
S. Haussühl
Keyword(s):  
Thermal Expansion ◽  
Elastic Constants ◽  
Elastic Anisotropy ◽  
Molecular Crystals ◽  
Organic Molecular Crystals ◽  
Anisotropy Of Thermal Expansion ◽  
Cauchy Relations

Abstract The elastic and thermoelastic constants of α-sulphur are measured by the Schaefer-Bergman method. The magnitude of the elastic constants is slightly higher than in comparable organic molecular crystals. The elastic anisotropy and the anisotropy of thermal expansion obey the Grüneisen relation. The deviations from the Cauchy relations are all negative. This is usually only observed in crystals with covalent bind­ing components or with a highly anharmonic behaviour.

scholarly journals A survey of thermal expansion coefficients for organic molecular crystals in the Cambridge Structural Database

2021 ◽  
Vol 77 (3) ◽  
Author(s):  
Andrew D. Bond
Keyword(s):  
Thermal Expansion ◽  
Standard Deviation ◽  
Linear Relationship ◽  
Molecular Crystals ◽  
Cambridge Structural Database ◽  
Normal Distributions ◽  
Organic Molecular Crystals ◽  
Thermal Expansion Coefficients ◽  
Structural Database ◽  
Expansion Coefficients

Typical ranges of thermal expansion coefficients are established for organic molecular crystals in the Cambridge Structural Database. The CSD Python API is used to extract 6201 crystal structures determined close to room temperature and at least one lower temperature down to 90 K. The data set is dominated by structure families with only two temperature points and is subject to various sources of error, including incorrect temperature reporting and missing flags for variable-pressure studies. For structure families comprising four or more temperature points in the range 90–300 K, a linear relationship between unit-cell volume and temperature is shown to be a reasonable approximation. For a selected subset of 210 structures showing an optimal linear fit, the volumetric expansion coefficient at 298 K has mean 173 p.p.m. K−1 and standard deviation 47 p.p.m.  K−1. The full set of 6201 structures shows a similar distribution, which is fitted by a normal distribution with mean 161 p.p.m. K−1 and standard deviation 51 p.p.m. K−1, with excess population in the tails mainly comprising unreliable entries. The distribution of principal expansion coefficients, extracted under the assumption of a linear relationship between length and temperature, shows a positive skew and can be approximated by two half normal distributions centred on 33 p.p.m. K−1 with standard deviations 40 p.p.m. K−1 (lower side) and 56 p.p.m. K−1 (upper side). The distribution for the full structure set is comparable to that of the test subset, and the overall frequency of biaxial and uniaxial negative thermal expansion is estimated to be < 5% and ∼30%, respectively. A measure of the expansion anisotropy shows a positively skewed distribution, similar to the principal expansion coefficients themselves, and ranges based on suggested half normal distributions are shown to highlight literature cases of exceptional thermal expansion.

scholarly journals Viscosity effect on the strategic kinetic overgrowth of molecular crystals in various morphologies: concave and octapod fullerene crystals

RSC Advances ◽  
2021 ◽  
Vol 11 (34) ◽  
pp. 20992-20996
Author(s):  
Kwangjin Song ◽  
Jin Young Koo ◽  
Hee Cheul Choi
Keyword(s):  
Molecular Crystals ◽  
Temperature Dependent ◽  
Temperature Dependent Viscosity ◽  
Viscosity Change ◽  
Organic Molecular Crystals ◽  
Viscosity Effect ◽  
Crystallization Solution ◽  
Dependent Viscosity

A kinetic overgrowth allowing organic molecular crystals in various morphologies is induced by temperature-dependent viscosity change of crystallization solution.

Solid state amorphization of organic molecular crystals using a vibrating mill

1995 ◽  
Vol 94 (12) ◽  
pp. 1013-1018 ◽  
Author(s):  
Itaru Tsukushi ◽  
Osamu Yamamuro ◽  
Takasuke Matsuo
Keyword(s):  
Solid State ◽  
Molecular Crystals ◽  
Organic Molecular Crystals ◽  
State Amorphization

scholarly journals Role of Conical Intersections on the Efficiency of Fluorescent Organic Molecular Crystals

2021 ◽  
Vol 125 (4) ◽  
pp. 1012-1024
Author(s):  
Miguel Rivera ◽  
Ljiljana Stojanović ◽  
Rachel Crespo-Otero
Keyword(s):  
Molecular Crystals ◽  
Conical Intersections ◽  
Organic Molecular Crystals

scholarly journals Temperature-Dependent Properties of Molten Li2BeF4 Salt Using Ab Initio Molecular Dynamics

ACS Omega ◽  
2021 ◽  
Author(s):  
Khagendra Baral ◽  
Saro San ◽  
Ridwan Sakidja ◽  
Adrien Couet ◽  
Kumar Sridharan ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Ab Initio Molecular Dynamics ◽  
Temperature Dependent ◽  
Temperature Dependent Properties
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