Structure: {Mo₇₂ Fe₃₀} - 30 paramagnetic Fe³⁺ ions (S = 5/2) embedded on the vertices of an icosidodecahedron

• WU Name: *fe30_map*_*
• Number of Spins: 30
• Number of Spins over all: 30
• CPU-time: ca. 1:05 hr (AMD XP 2600+)

General Informations:

In recent careful magnetic measurements of the Fe30 molecule done at the Ames Laboratory we have observed some strange features which could not have been detected before due to the sophisticated technique that one needs have at hand to perform such measurements. In order to understand these features we have proposed a new model description which takes into account small deviations from the ideal icosidodecahedron structure of the molecule and maps these onto the intra-molecular interaction scenario.

However, there is one unknown parameter which needs to be determined by subsequent comparison with the experimental data. In order to do so we need to perform a huge number of similar simulations which will be evaluated automatically and compared with the experiment! Using Spinhenge@home we distribute the whole calculation using several million work units! Our goal is to understand the reason for strange features recently detected in magnetic measurements of Fe30.


© 2005 H. Bögge

Structure: 29791 spins arranged on a three dimensional so-called SC lattice

• WU Name: SC_29791_cyc_*
• Number of Spins: 29791
• Number of Spins over all: 29791
• CPU-time: ca. 1:45 hr (AMD XP 2600+)

General Informations:

29791 spins arranged on a three dimensional so-called SC lattice. Here, SC means "simple cubic" with the property that each spin (yellow sphere) is interacting with its 6 nearest neighbors (red spheres). The figure on the right-hand side shows the SC unit cell in detail. The whole 3D structure is build of these little unit cells. To see the relation between the 3D structure and the unit cell just look at the grey sphere which is connected to the 3 next neighboring spins of that unit cell and to the 3 neighboring spins of 3 other unit cells adjacent to it.

With this calculation we want to test the efficiency of a new Monte Carlo routine and calculate the critical temperature of a large magnetic system. To do so we have to perform 250.000 Monte Carlo steps per temperature value ranging from 1 to 1000 Kelvin. Using Spinhenge@home we can distribute the whole calculation using more than 150.000 work units.