Show pageOld revisionsBacklinksBack to top This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong. ===== On the Coding of the Aggregate Spin Number ===== back to [[general#format_of_quantum_numbers|Documentaion for SPFIT and SPCAT]] The **aggregate spin number** is used in the **SPFIT** and **SPCAT** programs whenver more than six quantum numbers are needed to descibe a state – even if some of the quantum numbers are redundant. It can be decoded using information provided in the **.fit** file or the **.out** file after the list of parameters in both cases. The NH<sub>2</sub> example is used, in which //S// = 1/2, //I//<sub>N</sub> = 1, and //I//<sub>H</sub> = 1/2 for both H nuclei and **N** + **S** = **J**; **J** + **I**<sub>N</sub> = **F**<sub>1</sub>; **I**<sub>H1</sub> + **I**<sub>H2</sub> = **I**<sub>tot</sub>; and **F**<sub>1</sub> + **I**<sub>tot</sub> = **F**. **Please note:** The coding will be the same for equivalent spin combinations, meaning one spin of 1/2, one spin of 1, and two equivalent spins of 1/2. The coding will be different for other spin combinations, e. g. two spins of 1/2 and two equivalent spins of 1/2 with PH<sub>2</sub> as an example or one spin of 1, one spin of 1/2 and two equivalent spins of 1/2 with <sup>13</sup>CH<sub>2</sub> as an example. <code> BLOCK - WT - SYM - V - TSP - N - other quanta (rel. to F=0 ) 1 1 0 0 0 -2.5 -2.0 -1.0 1.0 </code> **TSP** is the aggregate spin number, here 0. Subsequently, //N// and the other quanta (//J//, //F//<sub>1</sub>, and //I//<sub>tot</sub>) are given **relative to //F// = 0**.\\ If we take, for example, line number 12: <code> 3 3 1 0 0 6 4 1 3 0 0 7 11686.80 </code> we see that for the upper state we have //N// = 3, hence //F// = 3 + 2.5 = 6 – 0.5 = 5.5, //J// = 3.5, //F//<sub>1</sub> = 4.5, and finally //I//<sub>tot</sub> = 1.0 is redundant.\\ Similarly for the upper state: //N// = 4, hence //F// = 6.5, //J// = 4.5, //F//<sub>1</sub> = 5.5, and finally //I//<sub>tot</sub> = 1.0 is again redundant.\\ For **TSP** = 1 we find: <code> 2 1 1 0 1 -1.5 -1.0 0.0 0.0 </code> For example in line 21 there is **TSP** = 1 twice: <code> 5 2 3 0 1 7 6 1 6 0 1 8 8749.68 </code> For the upper and lower state, respectively:\\ //N// = 5, //N// = 5.5, //F//<sub>1</sub> = 6.5, //I//<sub>tot</sub> = 0.0, and //F// = 6.5.\\ //N// = 6, //N// = 6.5, //F//<sub>1</sub> = 7.5, //I//<sub>tot</sub> = 0.0, and //F// = 7.5. back to [[general#format_of_quantum_numbers|Documentaion for SPFIT and SPCAT]] aggregate.txt Last modified: 2019/10/04 18:25by admin