Accurate ab initio treatment of alloy phases
Dnr:  SNIC 2015/428 
Type:  SNAC Small 
Principal Investigator:  Hossein Ehteshami 
Affiliation:  Kungliga Tekniska hÃ¶gskolan 
Start Date:  20150512 
End Date:  20180601 
Primary Classification:  10304: Den kondenserade materiens fysik 
Webpage:  
Allocation
Abstract
One pillar of modern material's design is density functional theory (DFT). In many circumstances DFT's calculations are as important as experimental results. Although in first principle or ab initio calculations, everything starts with few physical principles, in practice there are several approximations in order to make the calculations possible. Beside, several methods have been proposed to tackle KohnSham equations. Each of these methods has its own advantages and disadvantages. Site centered methods such as EMTO, LMTO and KKR plus coherent potential approximation (CPA) is a standard tool to treat alloy disorder in metals. Due to above mentioned approximation, there remain some systems which cannot be accurately treated by current status of the methods. One can name materials such as cemented carbide, nitride and oxide which are of interests for industries. For such systems, it is possible to use planewave methods but still it is difficult to treat alloy disorder in planewave methods. The main purpose of this project is to make use of accurate Exact muffintin orbital method (EMTO). New modules have been added to the code. Performing calculations are of great importance and interest for mentioned systems. Two industrially important alloys have been chosen to study namely pseudobinary Ti(O,C) and Zr(O,C). Since usually these carbide are made of its corresponding oxides, even in carbide there remains amount of oxygen in material. With newly developed method, these materials will be studied and effect of oxygen on thermodynamic stability of defects will be considered.
