Crystal Structure of Orthorhombic CaTa2O6.

Crystal Chemistry and Structure of the Orthorhombic (Fe,Mn)(Ta,Nb)2O6 Family of Compounds

In this paper we review the crystal chemistry and structure data from the literature and our results reported in the last decade for natural and synthetic samples of the tantalite-columbite series. Orderdisorder transitions and oxidation reactions on the ixiolite-columbite-wodginite system are reported for one Brazilian sample. It is shown that reports on these subjects are sometimes dubious an...

Structure of agkistrodotoxin in an orthorhombic crystal form with six molecules per asymmetric unit.

The structure of agkistrodotoxin crystallized under basic conditions has been determined at 2.8 A resolution by the molecular-replacement technique and refined to a crystallographic R factor of 0.194 and a free R factor of 0.260 with good stereochemistry. The molecular packing in the crystal differs from other PLA(2)s. The six molecules in the asymmetric unit form three dimers linked by Ca(2+) ...

Structure of the catalytic trimer of Methanococcus jannaschii aspartate transcarbamoylase in an orthorhombic crystal form.

Crystals of the catalytic subunit of Methanococcus jannaschii aspartate transcarbamoylase in an orthorhombic crystal form contain four crystallographically independent trimers which associate in pairs to form stable staggered complexes that are similar to each other and to a previously determined monoclinic C2 form. Each subunit has a sulfate in the central channel. The catalytic subunits in th...

Structure investigation of the (100) surface of the orthorhombic Al13Co4 crystal

STRUCTURE AND EXCITATIONS OF ORTHORHOMBIC Al3Co

We study the energetics of quasicrystals using a lattice gas simulation to sample atomic conngurations close to the quasicrystal and its approximants. The total potential energy for each connguration is calculated by summing electronic structure based pair potentials. We apply this method to study Al 73 Co 24 in a 14.4 A by 12.3 A by 8.1 A orthorhombic cell. The structures obtained are compared...