关注：

1）自由电子的DOS及能带结构；如free-electron like的碱金属的DOS及band;

2) 盐型化合物或electrides的DOS及能带结构；LiH,NaCl

3）上述结构的ELF及电荷密度、密度差图

4）其他待补充结构

题记：有的人，当你回想起他的时候，总是满怀感激。---- 转导师的信

   We are so glad youhave joined the group. I wanted to tell you some things about preparations forgood work here. And because I want to be sure that you understand these things,I have written them down.

1. English.

  It is not easy to work in a  foreign language, to understand and speak inEnglish. English was not my native language, so I sympathize with the struggleall people who come from elsewhere have. I think it should be obvious to youthat getting a workable command of English, spoken and written, is the toppriority for you in these  first days. Toward that end, I suggest thefollowing:

a) Findout what opportunities there are for taking English classes, and take every one possible. If you need to pay for some, we will pay it for you,up to some reasonable sum.

b) take every opportunity to speak at group meetings, commenting on what is being discussed,and bringing papers from the literature to the group meetings. One has to bebrave to do this.

c) thisis difficult: speak as much English as possible to your Chinese friends!

d) watch TV (I’m smiling) They speak too fast on TV, but it’s useful.

2. Physics and chemistry:

  You will soon see in the group, as you have seen from ourpapers,  that our primary interest is in understanding. We do calculations, of course, but out of these try to build qualitative (or mathematical) ideas, models that are of wider application than the specific numbers or chemical  compositions studied.

   It takes time for people entering the group to figure out how understanding is constructed out of numbers/calculations. Or to figure out how we use our understanding of the chemistry or physics of a system to check whether the calculations make sense or don’t (the computers are not intelligent, and we  make mistakes in what we ask them to do, so we need checks.)  

       Here are some specific suggestions:

a) pleasereview Ashcroft and Mermin, from which you probably studied.

b) for general inorganic chemistry, Green wood and Earnshaw  is a good text–  the whole book is available electronically, and several people in the group have physical copies. So if you want to know something about the chemistry of Sc, that’s the book to look in.

c) for quantumchemistry, a good text is by Lowe (I will give you a copy). For qualitative orbital pictures and also an introduction to molecular quantum chemistry, there is nothing better than Albright, Burdett, and Whangbo(I will give you a copy).

 And for a chemical view of bonding in the solid state, there is my book (available free on web) and Jeremy Burdett’s Chemical Bonding in Solids. Please read these, not all at once of course.

d) to build an intuition for electronic structure, it is useful to do some calculations (band structure and DOS), with VASP, for some typical substances representing common bonding types, all initially at 1 atm: diamond (an extendedcovalently bonded solid), nitrogen or CO2 (molecular crystals), NaCl or LiH (anionic crystal), Ni or Al (a metal), In each case test your intuition by predicting the number and width of the bands before you do the calculation.

  For an fcc metal do the calculation with the primitive unit cell, and in a conventional cubic one. Can you predict what will change and what will not?  Then repeat these calculations at a pressure of, say, 200 GPa in the same structure. Try to predict what will change and what will not.

    By confronting the predictions made before calculation with the results, I’ve found that an intuition is built up.

             Good luck,

xxx