Help Sheet for Getting Started with TeXsan

(ver 2.7 -- March, 2007)


1) Create your User Account

Create your user account using makeuser on BlueCHEX (see Help Sheet CREATING USER ACCOUNT).

Please note:  Nearly all commands in UNIX/Linux are in lower case.  Unix-type operating systems ARE case sensitive.  To this operating system:
"runbob" is very different from "RunBOB".  All commands should be typed as they appear in this help document.

2) Login to your User Account

On the Linux PC terminals (CHEXT1, CHEXT2 and CHEXT3), RMB on the black background and select BlueCHEX.  Enter your account name at the
"BLUECHEX Username:" prompt.

After the introductory messages you will be in your directory, which will have the same name as your account.  The prompt will look like:

<mydir>:/disk2/<mydir>

The initial password for your new account can be obtained from Dr. Hollander or any experienced user.  You will need (and want) to change it immediately after logging on.  To change the password; after you login, type:

passwd<CR>

at the prompt.  You will then be asked to enter the old password (do so) and to enter the new password twice.  Unix requires that passwords be 6 to 8 characters long and contain at least one numeral or alternative character.

3) Transfer your data files

Copy your data files from the Linux PC (ChexCSD) smartuse or apexuser account (as appropriate) using sftp

For data collected on the SMART instrument:
sftp smartuse@chexcsd

for data collected on the APEX instrument:
sftp apexuser@chexcsd

You will be asked a question to accept a security code, type "yes" at the prompt.  typing 'y' will not work, you need to type the full word "yes".

Enter the password at the prompt (it is the same one used to transfer your data from the Pentium computers in 32A Lewis when using goftp).

sftp> cd <mydir>

sftp> get *.hkl

sftp> get *.ins

sftp> get *m._ls

sftp> get *m.prp

sftp> get *s.out

sftp> bye

This will transfer all the necessary files from your integration to your account on BlueCHEX.  In addition, you should have already printed out the filenamem._ls, filenamem.prp and filenames.out files.

Alternatively, you can do the transfer, again via sftp, from the smartuse or apexuser accounts on chexcsd by typing:

sftp username@bluechex

After entering your password, you can then use the put command to transfer all the files noted above. Neither way is particularly "better" or "worse" for you.

Either way, get back to your account on Bluechex and at the prompt, type: dir2  This will show you a listing of the contents of your directory. Now type:  

<mydir>:/disk2/<mydir>  copy filenames.hkl f2.dat

This copies your absorption corrected data to the file "f2.dat".  This name is not optional.  TeXsan demands that the raw data file from SAINT/XPREP/SADABS be named f2.dat.

4) Start TeXsan

<mydir>:/disk2/<mydir>  texsan  &<CR> (Note that there is a space between "texsan" and "&"

This starts the program teXsan in an X-window.  Because we are using "foreign" data files the program will start out by asking us a series of questions about the crystal.  These questions will be in X-windows boxes.  Rather than try to duplicate those in this document, we will summarize the information being asked for.  All clicks are LMB.

Foreign Data Processing

Click on the proper crystal system, Laue group and lattice type.  Then click "Exit"

Foreign Data Processing

Click on the proper crystal system and Laue group and lattice. Then click "Exit".

Cell dimensions

Enter the idealized values of a, b, c, alpha, beta, gamma and their esd values. You will find these in your SAINT output. You can wipe a box by holding the LMB and moving the cursor, or you can move from box to box via the Tab key. The Del key does not back up, but rather draws the deleted data in from the right. (Linux calls this a "feature". I have my doubts.) Double-check your entries -- an error here can return to haunt you horribly. When all data is entered click on "Exit"

Radiation Type

Click on Mo, nothing else, then click on "Exit".

Title

The Box will start out with the words, "A TEXRAY.INF file is not present in this path/directory." While this is informative, it is also the title which will be used for your window if you don't change it. It also apparently generates problems for some of the programs. Please change it to whatever informative title you want to type, then click on "Exit".

Periodic Table - Formula Menu

Enter the empirical formula for your molecule by clicking on the atom-type in the periodic chart, then entering the number of atoms in the small box at top of the table, and clicking "OK" or hitting <CR>. When you are finished click on the lower box and enter the value of "Z" which you have calculated, then click on "OK" (<CR> will not work for this box -- I don't know why.) Click on "Exit" to finish.

Now there will be some writing on the screen which doesn't look too good, but it will get better later. You should start reading the manuals for Texsan now. (Well, actually, some time ago.)

5) Process Data

Pull down the Process menu and click on Process Raw Data. The program will process the data in f2.dat and write process.out. You should use the Print menu to print that file and inspect it. If Process did not assign a space group to your data, or if Process got it wrong (in your opinion) you will need to modify the space group under the Parameter menu.

6) Average your data:

Before you solve the structure you should average your data. Data averaging is under the HKL menu. Note that averaging can be "undone" later if you need to. WARNING!!: If your crystal is in the lowest symmetry group of all, P1, you must do your data averaging in XPREP. TeXsan will do it wrong!

All other space groups are apparently done correctly. The cause of this bug is still unknown.

6a) Do other things, like solve or refine the structure

7) Exit TeXsan

At some point you will log off for the night. Pull down the File menu and click on Exit, this will return you to the prompt.

<mydir>:/disk2/<mydir> bye<cr>

ALWAYS BE SURE TO EXIT TEXSAN AND TO LOG OUT BEFORE YOU CLOSE THE WINDOW. OTHERWISE THE SYSTEM WILL CONTINUE TO INSIST THAT YOU ARE LOGGED ON!

The window will collapse.