diff --git a/include/poet/DHT_Wrapper.hpp b/include/poet/DHT_Wrapper.hpp
index a74db4f2d..115d5e769 100644
--- a/include/poet/DHT_Wrapper.hpp
+++ b/include/poet/DHT_Wrapper.hpp
@@ -1,4 +1,4 @@
-//  Time-stamp: "Last modified 2023-08-15 14:57:51 mluebke"
+//  Time-stamp: "Last modified 2023-09-08 14:43:02 mluebke"
 
 /*
 ** Copyright (C) 2018-2021 Alexander Lindemann, Max Luebke (University of
@@ -89,7 +89,7 @@ public:
               const std::vector<std::int32_t> &key_indices,
               const std::vector<std::string> &output_names,
               const ChemistryParams::Chem_Hook_Functions &hooks,
-              uint32_t data_count);
+              uint32_t data_count, bool with_interp);
   /**
    * @brief Destroy the dht wrapper object
    *
@@ -240,7 +240,14 @@ private:
                         const std::vector<double> &new_results);
 
   std::vector<double>
-  inputAndRatesToOutput(const std::vector<double> &dht_data);
+  inputAndRatesToOutput(const std::vector<double> &dht_data,
+                        const std::vector<double> &input_values);
+
+  std::vector<double> outputToRates(const std::vector<double> &old_results,
+                                    const std::vector<double> &new_results);
+
+  std::vector<double> ratesToOutput(const std::vector<double> &dht_data,
+                                    const std::vector<double> &input_values);
 
   uint32_t dht_hits = 0;
   uint32_t dht_evictions = 0;
@@ -254,6 +261,7 @@ private:
   const std::vector<std::string> &output_names;
 
   const ChemistryParams::Chem_Hook_Functions &hooks;
+  const bool with_interp;
 
   DHT_ResultObject dht_results;
 
diff --git a/src/ChemistryModule/ChemistryModule.cpp b/src/ChemistryModule/ChemistryModule.cpp
index 3060e8617..a1b1a8837 100644
--- a/src/ChemistryModule/ChemistryModule.cpp
+++ b/src/ChemistryModule/ChemistryModule.cpp
@@ -378,9 +378,9 @@ void poet::ChemistryModule::initializeDHT(
 
     const std::uint64_t dht_size = size_mb * MB_FACTOR;
 
-    this->dht =
-        new DHT_Wrapper(dht_comm, dht_size, map_copy, key_indices,
-                        this->prop_names, params.hooks, this->prop_count);
+    this->dht = new DHT_Wrapper(dht_comm, dht_size, map_copy, key_indices,
+                                this->prop_names, params.hooks,
+                                this->prop_count, params.use_interp);
     this->dht->setBaseTotals(base_totals.at(0), base_totals.at(1));
   }
 }
diff --git a/src/ChemistryModule/SurrogateModels/DHT_Wrapper.cpp b/src/ChemistryModule/SurrogateModels/DHT_Wrapper.cpp
index d1ee112c2..af5fbf12e 100644
--- a/src/ChemistryModule/SurrogateModels/DHT_Wrapper.cpp
+++ b/src/ChemistryModule/SurrogateModels/DHT_Wrapper.cpp
@@ -1,4 +1,4 @@
-//  Time-stamp: "Last modified 2023-08-16 16:44:17 mluebke"
+//  Time-stamp: "Last modified 2023-09-08 22:09:03 mluebke"
 
 /*
 ** Copyright (C) 2018-2021 Alexander Lindemann, Max Luebke (University of
@@ -48,15 +48,17 @@ DHT_Wrapper::DHT_Wrapper(MPI_Comm dht_comm, std::uint64_t dht_size,
                          const std::vector<std::int32_t> &key_indices,
                          const std::vector<std::string> &_output_names,
                          const ChemistryParams::Chem_Hook_Functions &_hooks,
-                         uint32_t data_count)
+                         uint32_t data_count, bool _with_interp)
     : key_count(key_indices.size()), data_count(data_count),
       input_key_elements(key_indices), communicator(dht_comm),
-      key_species(key_species), output_names(_output_names), hooks(_hooks) {
+      key_species(key_species), output_names(_output_names), hooks(_hooks),
+      with_interp(_with_interp) {
   // initialize DHT object
   // key size = count of key elements + timestep
   uint32_t key_size = (key_count + 1) * sizeof(Lookup_Keyelement);
   uint32_t data_size =
-      (data_count + input_key_elements.size()) * sizeof(double);
+      (data_count + (with_interp ? input_key_elements.size() : 0)) *
+      sizeof(double);
   uint32_t buckets_per_process =
       static_cast<std::uint32_t>(dht_size / (data_size + key_size));
   dht_object = DHT_create(dht_comm, buckets_per_process, data_size, key_size,
@@ -93,8 +95,8 @@ auto DHT_Wrapper::checkDHT(WorkPackage &work_package)
 
   const auto length = work_package.size;
 
-  std::vector<double> bucket_writer(this->data_count +
-                                    input_key_elements.size());
+  std::vector<double> bucket_writer(
+      this->data_count + (with_interp ? input_key_elements.size() : 0));
 
   // loop over every grid cell contained in work package
   for (int i = 0; i < length; i++) {
@@ -107,7 +109,10 @@ auto DHT_Wrapper::checkDHT(WorkPackage &work_package)
 
     switch (res) {
     case DHT_SUCCESS:
-      work_package.output[i] = inputAndRatesToOutput(bucket_writer);
+      work_package.output[i] =
+          (with_interp
+               ? inputAndRatesToOutput(bucket_writer, work_package.input[i])
+               : bucket_writer);
       work_package.mapping[i] = CHEM_DHT;
       this->dht_hits++;
       break;
@@ -145,7 +150,10 @@ void DHT_Wrapper::fillDHT(const WorkPackage &work_package) {
       uint32_t proc, index;
       auto &key = dht_results.keys[i];
       const auto data =
-          outputToInputAndRates(work_package.input[i], work_package.output[i]);
+          (with_interp
+               ? outputToInputAndRates(work_package.input[i],
+                                       work_package.output[i])
+               : work_package.output[i]);
       // void *data = (void *)&(work_package[i * this->data_count]);
       // fuzz data (round, logarithm etc.)
 
@@ -165,7 +173,7 @@ void DHT_Wrapper::fillDHT(const WorkPackage &work_package) {
   }
 }
 
-std::vector<double>
+inline std::vector<double>
 DHT_Wrapper::outputToInputAndRates(const std::vector<double> &old_results,
                                    const std::vector<double> &new_results) {
   const int prefix_size = this->input_key_elements.size();
@@ -183,11 +191,12 @@ DHT_Wrapper::outputToInputAndRates(const std::vector<double> &old_results,
   return output;
 }
 
-std::vector<double>
-DHT_Wrapper::inputAndRatesToOutput(const std::vector<double> &dht_data) {
+inline std::vector<double>
+DHT_Wrapper::inputAndRatesToOutput(const std::vector<double> &dht_data,
+                                   const std::vector<double> &input_values) {
   const int prefix_size = this->input_key_elements.size();
 
-  std::vector<double> output{dht_data.begin() + prefix_size, dht_data.end()};
+  std::vector<double> output(input_values);
 
   for (int i = 0; i < prefix_size; i++) {
     const int data_elem_i = input_key_elements[i];
@@ -197,6 +206,30 @@ DHT_Wrapper::inputAndRatesToOutput(const std::vector<double> &dht_data) {
   return output;
 }
 
+inline std::vector<double>
+DHT_Wrapper::outputToRates(const std::vector<double> &old_results,
+                           const std::vector<double> &new_results) {
+  std::vector<double> output(new_results);
+
+  for (const auto &data_elem_i : input_key_elements) {
+    output[data_elem_i] -= old_results[data_elem_i];
+  }
+
+  return output;
+}
+
+inline std::vector<double>
+DHT_Wrapper::ratesToOutput(const std::vector<double> &dht_data,
+                           const std::vector<double> &input_values) {
+  std::vector<double> output(input_values);
+
+  for (const auto &data_elem_i : input_key_elements) {
+    output[data_elem_i] += dht_data[data_elem_i];
+  }
+
+  return output;
+}
+
 // void DHT_Wrapper::resultsToWP(std::vector<double> &work_package) {
 //   for (int i = 0; i < dht_results.length; i++) {
 //     if (!dht_results.needPhreeqc[i]) {