Dolomite or calcite, quartz and kaolinite in various proportions were reacted at 250-300~ temperatures and pressures up to 90 bars in a hydrous environment. Reactions which approached completion produced talc, calcite, montmorillonite, anorthite (both metastable hexagonal and stable triclinic polymorphs) and the rare Ca-zeolite, garronite. These reactions are applicable to diagenesis, low-grade...

The structure of the title salt, C(24)H(20)P(+)·H(8)B(3) (-), at 120 (2) K has triclinic (P1) symmetry with an unusual Z = 5, although there is pseudosymmetry observed with the tetraphenylphosphonium cations exhibiting I symmetry. One of the anions is disordered over two sets of sites with refined occupancies of 0.478 (11) and 0.522 (11).

Iron selenide obtained by mild hydrothermal reaction is not superconducting and exhibits a triclinic crystal structure below 60 K unlike superconducting FeSe from conventional solid state synthesis which is orthorhombic. In contrast, tetragonal iron sulphide FeS from hydrothermal synthesis is superconducting but undergoes no structural change on cooling.

1986). Since that time, new data have become available, and these have been incorporated into the monograph and taken into consideration in the present evaluation. 1.1.2 Structural and molecular formulae and relative molecular mass o Il H2C= CH-C-NH2 Relative molecular mass: 71.08 C3HsNO 1.1.3 Chemical and physical properties of the pure substance (a) Description: White crystalline solid (monoc...

The title compound, C(7)H(8)N(2)O(2), is monoclinic (space group P2(1)/n) at 295 (2) K with Z' = 2. The two types of molecule form independent C(7) chains, and the structure is related to that of the low-temperature triclinic polymorph, where Z' = 4 in P1, by a simple displacive transformation.

3-(2-Bromo-4-(1-methylethyl)phenyl)-1,1-dimethylurea was synthesized and structurally characterized at 296 K, 200 K and 140 K. A reversible thermal phase transformation was observed at ~170–180 K. On cooling, the structure transforms from a monoclinic to a triclinic crystal system. The isopropyl group is disordered above the phase transition temperature but is ordered below the transition tempe...

A Mathematical model has been considered to study the reflection and refraction phenomenon of plane wave at the interface of an isotropic liquid medium and a triclinic (anisotropic) half-space. The incident plane qP wave generates three types of reflected waves namely quasi-P (qP), quasi-SV (qSV) and quasi-SH (qSH) waves in the tric...