diff --git a/nafuma/xrd/refinement.py b/nafuma/xrd/refinement.py
index 64a98e8..8637a2c 100644
--- a/nafuma/xrd/refinement.py
+++ b/nafuma/xrd/refinement.py
@@ -1,24 +1,45 @@
 import os
 import shutil
 import time
+import re
 import datetime
+import warnings
 
 import nafuma.auxillary as aux
 
 def make_big_inp(data: dict, options={}):
+    ''' Generates a big .INP-file with all filenames found in data["path"]. Uses a template .INP-file (which has to be generated manually from an initial refinement in TOPAS) and appends this to a large .INP-file
+    while changing the filenames. '''
 
-    required_options = ['output', 'overwrite', 'backup', 'backup_path']
+    required_options = ['template', 'output', 'overwrite', 'backup', 'backup_dir', 'include', 'topas_options', 'save_dir', 'log', 'logfile']
 
     default_options = {
-        'output': 'big.inp', # Name of the output .INP file
+        'template': 'start.inp', # Name of the template .INP-file
+        'output': 'big.inp', # Name of the output .INP-file
         'overwrite': False, # Toggles overwrite on / off
         'backup': True, # Toggles backup on / off. Makes a backup of the file if it already exists. Only runs if overwrite is enabled.
-        'backup_dir': 'backup' # Specifies the path where the backup files should be located
+        'backup_dir': 'backup', # Specifies the path where the backup files should be located
+        'include': [],
+        'topas_options': {
+            'bootstrap_errors': None,
+            'A_matrix_memory_allowed_in_Mbytes': None,
+            'approximate_A': False,
+            'conserve_memory': False,
+            'do_errors': False,
+            'continue_after_convergence': False,
+            'num_runs': None,
+        },
+        'save_dir': 'results',
+        'log': False,
+        'logfile': f'{datetime.datetime.now().strftime("%Y-%m-%d_%H-%M-%S")}_generate_big_inp.log',
     }
 
     options = aux.update_options(options=options, required_options=required_options, default_options=default_options)
 
 
+    if not os.path.exists(options['template']):
+        raise Exception(f'Template file not found: {options["template"]}')
+
     # Raises exception if files exists and overwrite is not enabled
     if not options['overwrite']:
         if os.path.exists(options['output']):
@@ -27,8 +48,94 @@ def make_big_inp(data: dict, options={}):
 
     # Makes a backup of file
     elif options['backup'] and os.path.exists(options['output']):
+
+        if options['log']:
+            aux.write_log(message=f'File {options["output"]} already exists. Creating backup in {options["backup_dir"]}.')
+
         aux.backup_file(filename=options['output'], backup_dir=options['backup_dir'])
 
 
 
-    
\ No newline at end of file
+    runlist = os.path.join(os.path.dirname(options['output']), 'runlist.txt')
+    options['include'].append(runlist)
+
+    with open(options['template'], 'r') as template, open(options['output'], 'w', newline='\n') as output, open(runlist, 'w', newline='\n') as runlist:
+             
+        write_headers(output, options)
+        template = template.read()
+        
+        for i, path in enumerate(data['path']):
+
+            s = change_labels_and_paths(template, path, i, options)
+            output.write(s)
+            
+            runlist.write('#define \tUSE_'+f'{i}'.zfill(4) + '\n')
+
+
+
+def write_headers(fout, options):
+
+    for file in options['include']:
+        fout.write(f'#include {file} \n')
+
+    fout.write('\n')
+
+    for option, value in options['topas_options'].items():
+        if value:
+            fout.write(f'{option} {value} \n')
+
+
+
+def change_labels_and_paths(template, path, i, options):
+
+    temp_xdd = find_xdd_in_inp(options['template'])
+    
+    # Replace diffractogram-path
+    s = template.replace(temp_xdd, path).replace('XXXX', f'{i}'.zfill(4))
+
+    basename = os.path.basename(path).split(".")[0]
+    
+    # Define regular expressions for output lines
+    regs = [r'Out_Riet\([\S]*\)',
+            r'Out_CIF_STR\([\S]*\)',
+            r'Out_CIF_ADPs\([\S]*\)',
+            r'Out_CIF_Bonds_Angles\([\S]*\)',
+            r'Out_FCF\([\S]*\)',
+            r'Create_hklm_d_Th2_Ip_file\([\S]*\)',
+            r'out(.*?)append']
+    
+    # Define substitute strings for output lines
+    subs = [f'Out_Riet({options["save_dir"]}/{basename}_riet.xy)',
+            f'Out_CIF_STR({options["save_dir"]}/{basename}.cif))',
+            f'Out_CIF_ADPs({options["save_dir"]}/{basename}.cif))',
+            f'Out_CIF_Bonds_Angles({options["save_dir"]}/{basename}.cif))',
+            f'Out_FCF({options["save_dir"]}/{basename}.fcf)',
+            f'Create_hklm_d_Th2_Ip_file({options["save_dir"]}/{basename}_hkl.dat)',
+            f'out \t {options["save_dir"]}/{basename}_refined_params.dat']
+
+    # Substitute strings in output lines
+    for reg, sub in zip(regs, subs):
+        s = re.sub(reg, sub, s)
+
+
+    return s
+
+
+
+def find_xdd_in_inp(path):
+    ''' Finds the path to the .xy / .xye scan in a given .INP-file. Assumes only one occurence of xdd and will return the last one no matter what, but outputs a UserWarning if more than one xdd is found.'''
+
+    with open(path, 'r') as f:
+        lines = f.readlines()
+
+
+    xdds = 0
+    for line in lines:
+        if 'xdd' in line:
+            xdd = line.split()[-1].strip('"')
+            xdds += 1
+
+    if xdds > 1:
+        warnings.warn(f'More than one path was found in {path}. Returning last occurence - please make sure this is what you want!')
+
+    return xdd