diff options
Diffstat (limited to 'user/Atomlab/help.htc')
| -rw-r--r-- | user/Atomlab/help.htc | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/user/Atomlab/help.htc b/user/Atomlab/help.htc new file mode 100644 index 0000000..5f3b123 --- /dev/null +++ b/user/Atomlab/help.htc | |||
| @@ -0,0 +1,47 @@ | |||
| 1 | \clearance{} | ||
| 2 | \cache{\days{14}} | ||
| 3 | \page{ | ||
| 4 | <H1>AtomLab Help</H1> | ||
| 5 | <P> | ||
| 6 | <B>Atomlab</B> is a program which solves the Shrödinger equation for an isolated | ||
| 7 | atom. It takes a small set of parameters as input, and calculates the total energy | ||
| 8 | and radial distribution density of the system. The default is the setup for Be, | ||
| 9 | so if you want to know what the calculation looks like, just hit 'Run Program', | ||
| 10 | and you'll find out what you options are. | ||
| 11 | </P> | ||
| 12 | |||
| 13 | <H3>Input</H3> | ||
| 14 | <P> | ||
| 15 | <UL> | ||
| 16 | <LI><B>E<sub>xc</sub></B><BR> | ||
| 17 | The type of approximation used for the <I>exchange-correlation</I> energy, as | ||
| 18 | defined in DFT. | ||
| 19 | <LI><B>Ionicity</B><BR> | ||
| 20 | A figure of +1 here means the atom should have a total charge of +1. This is | ||
| 21 | accomplished by setting the atom number Z to the number of electrons N plus one, | ||
| 22 | <I>i.e,</I> Z = N+1. | ||
| 23 | <LI><B>Iterations</B><BR> | ||
| 24 | To keep the program from running for ever in cases where it has trouble converging. | ||
| 25 | The default value is reasonable for many systems. <B>Note</B>, however, that you | ||
| 26 | always must make sure that your system has converged properly, which is easiest done | ||
| 27 | by checking that the program quits before exceeding the maximum number of iterations. | ||
| 28 | <LI><B>Mixing</B><BR> | ||
| 29 | A method-dependent, technical parameter. Here it tells how much, going from one | ||
| 30 | iteration to the next, of the last tentative configuration should be 'remembered' | ||
| 31 | when calculating the new tentative configuration. | ||
| 32 | <LI><B>Electrons</B><BR> | ||
| 33 | An electron configuration of your choice. For instance, He has the utterly simple | ||
| 34 | configuration 1s<sup>2</sup>. Be has 1s<sup>2</sup>2s<sup>2</sup>, which is the default. | ||
| 35 | </UL> | ||
| 36 | </P> | ||
| 37 | |||
| 38 | <H3>Output</H3> | ||
| 39 | <P> | ||
| 40 | When running the program, the progress of the calculation is shown on-line in your | ||
| 41 | browser. After completion, you may optionally download the density distribution. | ||
| 42 | The file consists of three columns of data: distance, density and zero respectively, | ||
| 43 | all in appropriate atomic units. The file can be used immediately in for instance | ||
| 44 | <B>matlab</B>, by the command <B>load</B>. | ||
| 45 | </P> | ||
| 46 | <br><br> | ||
| 47 | } | ||
