diff --git a/README.md b/README.md
index c907c27..da35bf6 100644
--- a/README.md
+++ b/README.md
@@ -3,7 +3,7 @@ ARTS HITRAN cross section absorption model
 
 ## Calculate cross sections with the model
 
-1. Download the precalculated coefficients files from the `arts-xml-data` package and put them in the `coefficients/` directory.
+1. Download the precalculated coefficients files from the [`arts-cat-data`](https://www.radiativetransfer.org/tools/#arts-cat-data) package and put them in the `coefficients/` directory.
 
    To generate the coefficients yourself, see section ["Generate model coefficients"](#generate-model-coefficients) below.
 
diff --git a/scripts/Xsec_CalculateFitCoefficients.py b/scripts/Xsec_CalculateFitCoefficients.py
index 0c93070..ca6e3eb 100755
--- a/scripts/Xsec_CalculateFitCoefficients.py
+++ b/scripts/Xsec_CalculateFitCoefficients.py
@@ -160,10 +160,10 @@ def process_xsec_coefficients(species,
         # frequency in Hz
         freq = wvn * xaf.c0 * 100
 
-        # s_data_temp = pyarts.classes.GriddedField2()
+        # s_data_temp = pyarts.arts.GriddedField2()
         # s_data_temp.gridnames = ['frequency grid [Hz]', 'fit coefficients [m]']
-        # s_data_temp.grids = [pyarts.classes.Vector(freq),
-        #                      pyarts.classes.ArrayOfString(['p00', 'p10', 'p01', 'p20'])]
+        # s_data_temp.grids = [pyarts.arts.Vector(freq),
+        #                      pyarts.arts.ArrayOfString(['p00', 'p10', 'p01', 'p20'])]
         # s_data_temp.data = fit_coeffs.transpose()
         # s_data_temp.name = (species + '-band_' + str(band_no))
         s_data_temp = {}
@@ -997,7 +997,7 @@ def process_xsec_coefficients(species,
             coeff_file_name_arts = os.path.join(coeff_folder_arts,
                                                 species_arts + fid_arts)
 
-            fitdata_pyarts = pyarts.classes.XsecRecord.from_xarray(fitdata)
+            fitdata_pyarts = pyarts.arts.XsecRecord.from_xarray(fitdata)
             pyarts.xml.save(fitdata_pyarts,
                             coeff_file_name_arts,
                             precision='.14e',