Hi, I am refining a structure of 2.3A resolution. The R values with and without bulk solvent and anisotropic scale are quite different as you can see here: Start R-work = 0.3751, R-free = 0.5562 (no bulk solvent and anisotropic scale) Final R-work = 0.3741, R-free = 0.5557 (no bulk solvent and anisotropic scale) Start R-work = 0.2298, R-free = 0.2974 Final R-work = 0.2261, R-free = 0.2970 I checked the anisotropy of the data with different tools: Results from Xtriage: Maximum likelihood isotropic Wilson scaling ML estimate of overall B value of None: 39.25 A**2 Estimated -log of scale factor of None: -2.59 Maximum likelihood anisotropic Wilson scaling ML estimate of overall B_cart value of None: 50.10, 0.00, 0.00 50.10, -0.00 25.47 Equivalent representation as U_cif: 0.63, -0.00, -0.00 0.63, 0.00 0.32 Eigen analyses of B-cart: Value Vector Eigenvector 1 : 50.103 ( 0.71, 0.71, -0.00) Eigenvector 2 : 50.103 (-0.71, 0.71, -0.00) Eigenvector 3 : 25.473 (-0.00, 0.00, 1.00) ML estimate of -log of scale factor of None: -2.57 Correcting for anisotropy in the data Results from PHASER: Principal components of anisotropic part of B affecting observed amplitudes: eigenB (A^2) direction cosines (orthogonal coordinates) 8.178 0.9961 0.0879 0.0000 8.178 -0.0879 0.9961 0.0000 -16.357 -0.0000 -0.0000 1.0000 Anisotropic deltaB (i.e. range of principal components): 24.535 Results from Ctruncate: ANISOTROPY CORRECTION (using intensities): Anisotropic scaling (orthogonal coords): | -0.2272 -0.0000 -0.0000 | | -0.0000 -0.2272 0.0000 | | -0.0000 0.0000 0.4543 | Anisotropic U scaling (fractional coords): | -4.451e-05 -5.622e-23 -1.266e-21 | | -5.622e-23 -4.451e-05 -8.929e-22 | | -1.266e-21 -8.929e-22 4.717e-06 | Anisotropic B scaling (fractional coords): | -3.514e-03 -4.439e-21 -9.995e-20 | | -4.439e-21 -3.514e-03 -7.050e-20 | | -9.995e-20 -7.050e-20 3.725e-04 | Eigenvalues: 0.7728 0.7728 1.4543 Eigenvalue ratios: 0.5314 0.5314 1.0000 Resolution limit in weakest direction = 3.156 A Now I am not sure about the severeness of anisotropy and the necessary procedure and would be very pleased if anyone could help. The electron density maps look okay related to the resolution. Has anyone experience with the diffraction anisotropy server or ellipsoidal truncation with data with comparable anisotropy? Thank you for your help in advance Ina Ina Lindemann Philipps-Universität Marburg Pharmazeutische Chemie AG Klebe Marbacher Weg 6 35032 Marburg Tel.: 06421/2825908